Veterinary Education

7 Reasons Your Deworming Program Isn’t Working

Tue, 12 May 2026 18:09:13 GMT

For many producers, deworming has become a routine part of herd management. Cattle are processed, products are administered and the expectation is that parasite control is handled for another season.

But across the industry, cattle continue to underperform despite regular treatment. In many cases, the issue is not a single product failure, but a combination of resistance pressure, hidden production losses and management habits that gradually reduce the effectiveness of parasite control programs over time.

On the most recent episode of “ The Bovine Vet Podcast ,” Megan Bollin, a technical services veterinarian with Norbrook, and Nancy Jackson, a field veterinarian for the Mississippi Board of Animal Health, outlined several reasons why deworming programs may not be delivering the results producers expect.

1. Subclinical Parasites May Be Hurting Performance Before You Notice

Parasites do not need to cause obvious disease to affect productivity. In many cases, the biggest losses are occurring quietly through reduced digestion, feed efficiency and weight gain.

“Those parasites are going in and doing damage to the lining of the abomasum, and so what normally should be a lower pH is actually becoming more neutral. That impacts protein digestion, nutrient absorption and even appetite. It reduces voluntary feed intake, and then that cascades into average daily gain, feed efficiency, milk production and reproductive performance,” Bollin explains.

Because those effects develop gradually, they are often difficult to recognize without measurement.

“They’re those silent robbers that are there. We can’t really see them, and that’s why it’s called a subclinical impact, but they’re doing major damage,” Bollin says.

Jackson notes some calves may visibly underperform, but many losses remain subtle enough that producers underestimate the impact.

“You can see it in some cases, calves just standing there, not grazing, not performing, but a lot of times producers don’t realize what they’ve lost because they’re not measuring it,” Jackson says.

2. Resistance Is Already Present on Many Operations

Reduced dewormer efficacy is no longer considered a future concern. Parasite susceptibility can now vary significantly between farms, even within the same geographic region.

“Even from one side of the county to the other, recommendations might be very different depending on pasture type, parasite exposure and treatment history,” Bollin says.

That variability makes it increasingly difficult to assume a protocol that works well on one operation will perform the same way elsewhere.

At the same time, few replacement products are expected in the near future.

“We’ve routinely given the same things over and over, and we don’t have any new molecules on the horizon,” Bollin explains.

As resistance pressure increases, reduced efficacy in existing products can have growing consequences for cattle performance and long-term parasite control.

3. You May Be Underdosing More Often Than You Think

One of the most common management issues contributing to reduced efficacy is underdosing. As cattle size has increased over time, dose estimates have not always kept pace.

“Our producers still think they have a 1,000-lb. cow, but cows have been getting bigger for years. So, we’ve probably been underdosing cattle, especially those larger animals and bulls.” Jackson warns.

Underdosing exposes parasites to a drug without fully eliminating them, increasing the likelihood that surviving worms contributes to future resistance problems.

4. Some Dewormers Are Being Used Like Fly Control Products

Convenience can also create problems when products are used outside their intended purpose.

According to Jackson, some producers are administering pour-on dewormers at partial doses primarily for fly control rather than at labeled doses intended to control internal parasites. Repeated exposure to subtherapeutic drug levels creates ideal conditions for resistant parasites to survive and spread.

5. Poor Record-Keeping Makes Resistance Harder to Detect

Inconsistent product tracking can make parasite control decisions much more difficult over time. Without knowing which active ingredients or drug classes have been used previously, producers may unknowingly rely on the same class repeatedly or struggle to evaluate whether a protocol is still effective.

“I’ll ask what they used, and they’ll say, ‘It was the blue one’ or ‘I got it off the shelf at the co-op.’ But we need to know the active ingredient to make good decisions,” Jackson says.

That lack of detail can make it harder to identify emerging resistance patterns before they become more significant problems.

6. Application Problems Can Look Like Resistance

Not every apparent treatment failure is true resistance. In some cases, the problem lies in how the product was administered.

“There are a lot of things that have to go right with a pour-on for it to work. If the animal is dirty, that product isn’t going to get absorbed. If it rains, it can dilute it. Oral products can be spit out. There are a lot of factors that can look like resistance but aren’t,” Bollin explains.

Without recognizing those factors, producers may incorrectly conclude that resistance is solely to blame.

7. Parasite Problems Don’t Stay on One Farm

The effects of ineffective parasite control can extend well beyond a single operation. As calves move through the production chain, resistant parasite populations can move with them, affecting downstream performance and management decisions.

“When those calves leave your place, you’re passing that parasite load on to someone else. If it’s resistant, it affects the feedlot and performance down the line,” Jackson warns.

That interconnectedness means small failures repeated across multiple operations can gradually reshape parasite pressure across the industry.

Why Parasite Problems Keep Building

Many deworming programs do not fail because of one dramatic mistake. Instead, they lose effectiveness gradually through repeated small issues: underdosing, inconsistent application, misuse of products and resistance pressure that goes unnoticed until performance has already been affected.

Routine treatment schedules alone are no longer guaranteeing consistent outcomes, particularly when the surrounding management practices remain inconsistent. This means parasite control is becoming less about whether cattle are treated and more about how those treatments are being used and how the results are being monitored over time.

To hear more from Bollin and Jackson on how deworming strategies may be falling short, and how strategies are evolving, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

Beef-on-Dairy Calves May Scour Less than Holsteins, New Research Shows

Mon, 11 May 2026 18:44:38 GMT

Beef-on-dairy calves have long been a solid income stream on many dairies, turning into a steady payout when they leave the farm and move into beef systems. More recently, farmers have also started to notice these calves often require fewer individual health treatments than their purebred counterparts, adding to their overall profitability.

Researchers like Melinda Kovacs, a master’s student at the University of Guelph, have started to take a closer look at how these calves perform early in life, when most health challenges tend to show up. One pattern that keeps surfacing is that crossbred calves tend to have fewer digestive issues than Holsteins, especially scours.

In her work, Kovacs found beef-on-dairy crossbred calves have lower diarrhea rates, fewer days with scours and fewer repeat treatments than Holsteins during the rearing phase.

“Producers were finding that the health of these crossbred calves was improved,” Kovacs explained during a recent “The Dairy Health Blackbelt Podcast” episode. “They were finding less health challenges, or these animals were able to recover from disease a little bit better than the purebred calves.”

Fewer Scours Cases Stand Out

The study followed approximately 640 calves housed at a single calf-rearing facility over about 18 months. Kovacs analyzed records from 446 Holstein calves and 194 beef-on-dairy crossbred calves.

Using twice-daily health scoring, Kovacs and her team monitored diarrhea and respiratory disease while also collecting weekly body weights, milk intake and starter feed intake data.

When she compared the two groups at the conclusion of the study, one health challenge stood out immediately.

“We found that the Holstein calves had a higher incidence of diarrhea compared to the crossbred calves,” Kovacs says. “We also found that translated to fewer days with diarrhea.”

Beef-on-dairy calves_Suanne Blackwell

(Suanne Blackwell)

The same trend appeared when she evaluated severe diarrhea cases.

“This is what we were expecting based on kind of our communication with producers,” Kovacs says. “That the crossbred calves would have less diarrhea in the preweaning or the rearing phase.”

For dairy farmers and calf raisers, fewer scours cases can influence nearly every part of calf performance. Diarrhea remains one of the most expensive calfhood diseases on dairies due to treatment costs, lost growth, labor demands and long-term health setbacks.

Crossbred Calves Needed Fewer Repeat Treatments

Kovacs also examined therapeutic interventions and found another difference between the groups.

“We did find that the Holstein calves had a higher hazard of being treated multiple times for both diarrhea and respiratory disease,” she says.

Respiratory disease rates themselves were similar between breeds, but the need for repeated treatment was higher in Holsteins. That finding could become more important as dairy and calf-rearing operations focus on reducing antibiotic use while still keeping calves healthy and performing well.

“Perhaps there’s a greater ability of these crossbred calves to recover from diseases compared to Holstein calves,” Kovacs adds.

Why Are Beef-on-Dairy Calves More Resilient?

(Farm Journal)

The study wasn’t designed to pin down exactly why the differences are showing up, but Kovacs thinks genetics likely play a role.

“In the dairy industry, we see a lot of inbreeding depression with the Holstein animals,” she says. “And I think perhaps we have some heterosis or hybrid vigor in these crossbred animals.”

Selection pressure may also contribute to the performance gap. Dairy genetics have focused on milk production traits, while beef genetics have emphasized growth and muscling.

“In the dairy industry, we’ve been genetically selecting for obviously higher milk production, whereas in the beef industry, we’ve been selecting for more growth traits,” Kovacs says. “So perhaps these crossbred calves are benefiting from the growth traits compared to the Holstein calves.”

She also found crossbred calves gained weight faster during the rearing phase.

“The crossbred calves did have higher growth rates, so higher average daily gains,” Kovacs says. “They were about [15 lb.] heavier than the Holstein calves when they were finished this rearing phase.”

Differences Continued Through Harvest

Kovacs and her team later expanded the project to follow some calves from birth through harvest at approximately 13 months of age. She wanted to better understand how calfhood health and management influence later feedlot and carcass performance.

Beef_carcasses

“Right now, there’s kind of a big disconnect between all of the different components of the industry, between the dairy farm of origin, the rearing, the feedlot and the abattoir,” Kovacs says.

The performance differences continued beyond the early rearing phase.

“The crossbred calves, I believe, were about [120 to 124 lb.] more in body weight compared to the Holsteins,” Kovacs says. “Which does have significant implications in terms of the cost benefit of these animals.”

She also identified differences in ribeye area and carcass composition, suggesting the advantages weren’t limited to early growth but carried through to how the animals finished at harvest.

More Research Still Needed

Even with the encouraging results, Kovacs says dairy producers should not assume crossbred calves require less attention or lower-quality care.

“With my findings, we see that they’re maybe more resilient or robust,” she says. “But I think those producers still need to be offering the best care to those calves to ensure their success.”

Kovacs adds that much of the existing calf research has historically focused on purebred Holsteins, leaving major knowledge gaps around nutrition and management requirements for beef-on-dairy calves.

“A lot of research that’s been done in the past has focused on purebred Holstein calves,” Kovacs says. “So, we don’t really know if the requirements of these crossbred calves for both maintenance and growth are the same as for a purebred Holstein calf.”

As beef-on-dairy programs continue to expand across the dairy industry, producers are paying closer attention to which calves stay healthier and perform better from start to finish. This research suggests fewer scours cases early in life may be part of the advantage, adding to the overall profitability of beef-on-dairy calves.

For more on beef-on-dairy, read:

The New Rules of Parasite Control

Thu, 07 May 2026 19:35:27 GMT

For decades, parasite control in cattle has followed a familiar script: Treat the whole herd in the spring, treat again in the fall and trust that the job is done. It’s simple, efficient and deeply ingrained in how many operations function.

But that approach is starting to shift.

On the most recent episode of “ The Bovine Vet Podcast ,” Megan Bollin, a technical services veterinarian with Norbrook, and Nancy Jackson, a field veterinarian for the Mississippi Board of Animal Health, describe an industry moving away from routine, whole-herd deworming and toward a more strategic, data-driven approach.

At the center of that shift is a fundamental change in thinking. As Bollin explains, the goal is no longer the complete elimination of parasites but rather smarter management of them.

“Historically, we’ve had the mindset of just getting rid of all the parasites, right? One-hundred percent — we want them all gone. But we’ve got to consider that 90% of the life cycle is in the pasture. So we’ve got to learn to live with these parasites,” Bollin says.

Why Routine Deworming Falls Short

Routine deworming became standard for a reason. It aligned with when cattle were already being handled, minimized labor and offered a straightforward protocol producers could repeat year after year. The problem is that convenience doesn’t always align with biology. Treating cattle when they are easiest to handle may not coincide with the most effective point in the parasite life cycle, which ultimately limits the return on treatment.

“It may be a convenient time when we have them caught, and I know it takes a lot of labor and planning and resources to get those animals through the chute and treat them, but it may not be the most economically beneficial time to treat them if we’re not applying that product at the correct time in the life cycle,” Bollin says.

Because most of the parasite life cycle occurs on pasture rather than in the animal, poorly timed treatments can miss the window where they would have the greatest impact. The result is a system that feels consistent but may not be working as efficiently as intended.

Replacing Guesswork With Diagnostics

As parasite control becomes more strategic, diagnostics are moving from optional to essential. Instead of relying on assumptions or visible signs, producers are increasingly being encouraged to measure parasite burden directly.

Fecal egg count testing provides a snapshot of parasite burden by quantifying the number of parasite eggs present in a manure sample, giving a measurable baseline rather than relying on assumption. Building on that, the fecal egg count reduction test (FECRT) evaluates how well a dewormer is working by comparing egg counts before and after treatment — typically 10 to 14 days later — to determine the percentage reduction. A reduction of around 95% is generally considered indicative of effective treatment, while lower reductions may signal reduced efficacy or emerging resistance.

Together, these tools allow parasite control decisions to be based on data, helping tailor treatment strategies to the specific conditions of each herd rather than applying a one-size-fits-all approach.

“If you’re doing just a straight fecal egg count, it needs to be quantitative. A qualitative test — just saying whether parasites are there or not — is not helpful, because you’re always going to have parasites,” Bollin advises.

Those baseline measurements allow for informed decisions about whether treatment is needed and how well products are performing. Follow-up testing is just as important, helping confirm whether a dewormer is still effective.

Rather than relying on routine schedules, this approach acknowledges that treatment decisions vary from one operation to the next.

“There’s no magic number that says you need to treat at this high of an egg count,” Bollin says. “It’s going to depend on your geography, your herd and your operation.”

That variability is something producers already manage in other aspects of their operation. As Jackson notes, parasite control should be approached with the same level of flexibility.

“Every farm is unique — when they calve, when they wean — so it’s hard to make a cookie-cutter template,” Jackson says.

In many cases, the need for measurement comes down to what isn’t immediately visible. Subclinical parasite burdens can quietly reduce performance without obvious warning signs, making data even more valuable.

Refugia: A Counterintuitive but Critical Strategy

Rather than treating every animal, every time, the concept of refugia encourages leaving a portion of the parasite population unexposed to dewormers. Bollin explains that this approach helps preserve drug effectiveness by maintaining a population of parasites that remain susceptible, rather than selecting only for those that survive treatment.

“Refugia is leaving a percentage of the parasites unexposed to a dewormer. The idea is that resistance is a heritable trait, so we’re trying to dilute those resistance genes and maintain a population of parasites that are still susceptible to the products we have available,” Bollin says.

While it may seem counterintuitive, this strategy reflects a broader shift away from trying to eliminate parasites entirely and toward managing them in a way that sustains long-term control.

Implementing refugia doesn’t mean abandoning treatment. Instead, it means focusing on the animals that benefit most.

“We know that calves are going to be more susceptible, so ideally we want to treat those animals. But those mature cows — if they’re in good condition and have good nutrition — their immune system should be able to suppress those parasites,” Bollin says.

This kind of targeted approach allows producers to use dewormers more effectively while also supporting broader parasite management goals.

Combining Classes to Improve Efficacy

While refugia focuses on preserving a population of susceptible parasites, another strategy aims to improve how effectively treated parasites are eliminated. Combination deworming, or the concurrent administration of anthelmintics from different drug classes, is increasingly being used to improve efficacy in the face of variable parasite susceptibility.

Because these classes act through distinct mechanisms — such as macrocyclic lactones targeting parasite neuromuscular function and benzimidazoles disrupting microtubule formation — using them together can increase overall parasite kill and reduce the proportion of resistant survivors. The benefit becomes clear when considering how efficacy compounds across treatments.

“If you have 100 worms and you go in with a product that has 80% efficacy, you’re left with 20. Then you come in with a second dewormer, also at 80% efficacy, and it kills 80% of those 20. So you go from 80% efficacy up to 96% by using two products with different mechanisms of action,” Bollin explains.

This additive effect can help achieve the reduction typically associated with effective control, particularly on operations where single products no longer meet that threshold. Used alongside approaches like refugia and diagnostic-guided treatment, combination therapy becomes part of a broader strategy aimed at maintaining both short-term efficacy and long-term sustainability.

A More Strategic Future

Taken together, these changes represent a shift away from routine and toward precision parasite management. Instead of relying on fixed schedules, producers are being encouraged to align treatments with parasite biology, use diagnostics to guide decisions and adjust protocols over time.

That shift requires a willingness to rethink long-standing habits. As Jackson points out, progress often starts with being open to change: “We’ve always done it a certain way, but there’s always room to learn and adjust how we’re managing these parasites.”

It also depends on continued collaboration and learning across the industry. Parasite control is not a one-time decision but rather an ongoing process that evolves with new information.

“It’s continual education for both the producer and the veterinarian to understand the life cycle and apply that information to the herd,” Jackson says.

Ultimately, the goal is to move beyond routine and toward more intentional decision-making.

“I think very simply, it’s about not doing it on guesswork like we have been for decades; it’s about using the science and the tools that we have available and being more strategic about how and when we treat,” Bollin says.

Parasites are not going away, but the way they are managed is evolving. Producers who adapt to these new rules will be better positioned to protect both animal performance and the tools they rely on to sustain it.

To hear more from Bollin and Jackson on how deworming strategies are evolving, including where current protocols are falling short, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

How to Be the Best Veterinary Mentor

Tue, 21 Apr 2026 22:03:08 GMT

Mentorship in veterinary medicine is often treated as something informal. A student rides along, watches a few cases, asks a few questions and moves on.

In reality, those early experiences shape how new veterinarians think, work and handle pressure. The difference between a student who leaves confident and one who leaves overwhelmed often comes down to how intentional that mentorship was.

These mentorships can be just as beneficial for the mentor veterinarian. Dr. Erika Nagorske, bovine veterinarian with Four Star Veterinary Service, regularly takes on mentees as a mutually beneficial scenario.

“It’s like the refresher of the medicine and the science, because they ask so many good questions. And that’s what I want it to be. I want it to be very open and fluid,” Nagorske says.

Good mentorship does not require a complete overhaul of the day. It requires a shift in mindset. When a student is with you, the goal is no longer efficiency, but education.

1. Prepare for the Day to Take Longer

The simplest adjustment is also the most important: expect the day to slow down.

“Just mentally prepare yourself. Things are going to take longer. And that’s okay,” Nagorske says.

Explaining decisions, answering questions and creating space for hands-on learning all take time. Trying to maintain a full-speed schedule while mentoring often leads to frustration for both the veterinarian and the student.

Planning ahead can help. That might mean building extra time into certain calls or accepting that the day will not run as tightly as usual. When that expectation is set early, the experience improves for everyone involved.

2. Let Them do the Work

Observation alone is not enough to prepare students for practice. They need the opportunity to participate.

“Even if it’s just letting them close one layer of an incision. That’s not going to ruin your day, but it’s going to make their day really, really good,” Nagorske says.

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A post shared by Dr. Erika Nagorske (@docnagorske)

Hands-on experience builds confidence in a way that observation cannot. Even small tasks can help students feel engaged and capable, rather than passive.

Those opportunities also make the transition into practice less abrupt. When students have already performed parts of a procedure or worked through a case, they are better prepared for the moment when they are the one making decisions.

“The next time they see it, they might be the doctor. So let them do it, let them ask all the questions and walk them through everything,” Nagorske encourages.

3. Create a Safe Space to Fail

One of the most valuable things a mentor can provide is a controlled environment where mistakes are allowed.

“You need a safe place to fail, because the last thing you want is your failure to totally ruin you,” Nagorske says.

Students often come into clinical settings with high expectations of themselves. When something goes wrong, it can feel disproportionately significant. A strong mentor helps reframe those moments.

That does not mean ignoring risk. Patient safety comes first. It does mean allowing students to work through situations when appropriate, stepping in when necessary and using those moments as teaching opportunities rather than failures.

4. Take Care of the Basics

Mentorship is not only about medicine. It is also about recognizing the student is navigating a new, and often uncomfortable, environment.

“That sounds so silly, but I remember many situations where I was like, ‘I think I might pee my pants, and I feel so bad asking to stop,’” Nagorske says.

Students are often hesitant to speak up about basic needs. They do not want to interrupt the flow of the day or create inconvenience. That hesitation can turn what should be a positive experience into a stressful one.

Taking a moment to check in about food, breaks and expectations for the day creates a more supportive environment and allows the student to focus on learning.

5. Take Photos of Them

Some of the most impactful parts of mentorship are also the easiest to overlook.

“They love it. I’m always just like their personal paparazzi, taking pictures while they’re doing stuff,” Nagorske says.

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A post shared by Dr. Erika Nagorske (@docnagorske)

With permission from both the student and the producer, capturing those moments can be meaningful. It gives students something tangible to take away from the experience and reinforces that they were an active participant, not just an observer.

6. Be Intentional About the Experience

Not every veterinarian enjoys teaching, and that is worth acknowledging. Mentorship takes time, patience and effort.

When a student is present, the experience should be purposeful. That does not mean every moment needs to be structured, but it does mean making an effort to include them, challenge them and support them.

Mentorship does not need to be perfect to be effective, but in a profession where the transition into practice can be difficult, intentional mentorship can make a lasting difference.

Thoracic Ultrasound is Changing How We Detect Pneumonia in Calves

Wed, 08 Apr 2026 15:11:50 GMT

“If you don’t use lung ultrasound, you won’t catch a lot of pneumonia cases,” says Sebastián Umaña Sedó, assistant professor of production management medicine, VA-MD College of Veterinary Medicine at Virginia Tech.

That statement reflects a growing reality in calf health, and it is backed by field data.

In a new multistate dataset presented by Umaña Sedó of 357 dairy calves across 34 farms in Virginia, Pennsylvania and North Carolina, roughly 30% of calves showed some form of respiratory disease between 22 and 60 days of age. Clinical pneumonia and subclinical pneumonia occurred at nearly identical rates, each accounting for about 10% to 11% of cases.

This is a substantial portion of pneumonia occurring in calves that would appear normal during routine observation.

Why Health Scoring Alone Isn’t Enough

Subclinical pneumonia often goes undetected because calves can appear healthy despite significant lung lesions. Standard respiratory scoring systems remain useful, but they have a critical blind spot.

“Clinical pneumonia is when we have a positive health score and positive ultrasound … subclinical pneumonia is when the health score is negative but the ultrasound is positive,” Umaña Sedó says, emphasizing that ultrasound is essential to identify subclinical cases. Calves can pass a health exam and still have meaningful lung pathology.

“If you do a health score on one calf, you might say the calf is healthy, but in reality it has a compromised lung. So there can be a disassociation between what you see clinically and what is actually happening in the lung,” he explains.

This gap between appearance and pathology allows disease to progress unnoticed, often until treatment becomes more difficult and more costly.

The Real Cost of Delayed Detection

Missed or late-detected pneumonia carries real economic consequences, even when cases are eventually treated.

“A case of pneumonia is around $300, and this is just the first treatment. Most of these animals need two treatments,” Umaña Sedó says.

In addition to direct treatment costs, delayed pneumonia detection is associated with higher retreatment rates, increased antimicrobial use and reduced growth and future productivity. At the same time, subclinical cases may go undetected entirely, quietly impacting performance without ever being formally diagnosed.

What Thoracic Ultrasound Changes

Thoracic ultrasound addresses this gap by allowing veterinarians to assess the lung directly rather than relying solely on outward signs.

“It really helped to change the health of these calves by detecting pneumonia way earlier,” Umaña Sedó says.

With ultrasound, practitioners can:

Detect lung consolidation earlier
Differentiate upper versus lower respiratory disease
Identify cases that actually require antimicrobial treatment
Monitor response to therapy

This shift enables earlier, more precise and more confident intervention.

Set Ultrasound Benchmarks

As adoption increases, thoracic ultrasound is moving beyond diagnosis and becoming a tool for herd-level monitoring and decision-making.

Umaña Sedó highlights practical Wean Clean benchmarks set forth by The Dairyland Initiative at the University of Wisconsin-Madison that farms can use to evaluate their respiratory programs:

At the start of weaning: Fewer than 15% of calves should have evidence of pneumonia
At first treatment: Fewer than 15% of calves should have advanced lung lesions (score greater than 3)
→ Higher levels suggest disease is being detected too late
7 to 10 days after treatment: Fewer than 15% of calves should still show significant lesions (score greater than 2)
→ Higher levels may indicate treatment failure or relapse

Together, these benchmarks provide a way to evaluate both timing and effectiveness of intervention.

How to Start Using Ultrasound On-Farm

For many operations, implementation begins with a simple, targeted approach.

“The way I started with this was scanning animals that were not getting better … and then showing the producer what we were finding and how treatment could change based on that,” Umaña Sedó explains.

That initial step helps demonstrate value quickly and builds confidence in the tool.

“You start with a few animals, and as you get results, you can expand — scan 10 to 12 calves every week and follow them through weaning,” he suggests.

One structured approach is the 12 × 7 strategy, which involves beginning scans at seven days of age, evaluating a group of 12 calves and repeating that process every seven days. Over time, this helps identify when calves are most at risk and supports more proactive management.

From Better Decisions to Proactive Care

Thoracic ultrasound is not only improving how pneumonia is detected; it is also reshaping how treatment decisions are made.

“Right now, we’re treating some of those cases with anti-inflammatories instead of antimicrobials, because we’re scanning constantly and we have that data,” Umaña Sedó says.

By distinguishing true pneumonia from upper respiratory disease, ultrasound allows for more targeted antimicrobial use, reduces unnecessary treatments and better aligns calf health programs with antimicrobial stewardship goals.

More broadly, thoracic ultrasound reflects a shift in how calf respiratory disease is managed. Instead of reacting to visible illness, veterinarians can detect disease earlier, better understand its true prevalence within a herd and continuously refine treatment protocols based on real data.

In doing so, they are not just improving detection, but redefining what effective pneumonia management looks like.

Rethinking Milk Fever in Dairy Cows: How the Immune System Impacts Calcium Levels

Tue, 07 Apr 2026 19:50:26 GMT

Milk fever has long been framed as a calcium problem. But what if that framing is too narrow and part of the reason prevention strategies don’t always deliver consistent results?

Work from Burim Ametaj , Professor at the University of Alberta and recent guest on “The Bovine Vet Podcast” , is helping reframe hypocalcemia through what he terms the calci-inflammatory network — a model that links calcium dynamics directly to immune function during the transition period.

A Common Problem, Often Hidden

Milk fever remains one of the most widespread metabolic disorders in dairy cattle, but much of its impact is hidden in subclinical cases.

“Milk fever is widespread, but now we have this subclinical part of milk fever that is not visible. You need to get a blood sample to measure calcium to determine, based on the concentration of calcium in blood, whether the cow is going through subclinical milk fever or clinical milk fever,” Ametaj says.

These subclinical cases lack obvious signs, yet they are consistently linked to reduced intake, impaired immune function and increased risk of diseases such as mastitis , metritis and ketosis.

Despite decades of focus on calcium supplementation and DCAD strategies, hypocalcemia remains prevalent. This has prompted a closer look at the underlying biology.

(Farm Journal)

Total Versus Ionized Calcium: A Critical Distinction

A key refinement in this emerging framework is the distinction between total calcium and ionized calcium. While total calcium is commonly measured, much of it is bound to proteins like albumin or other molecules. Only a fraction exists as ionized calcium — the biologically active form required for muscle contraction, nerve signaling and immune cell function.

This distinction has important implications for treatment. While calcium borogluconate is a known treatment for hypocalcemia in cattle, Ametaj suggests it may not be ideal for ionized calcium availability.

“What happens?” asks Ametaj about blood ionized calcium levels when an animal receives calcium borogluconate. “It is decreased, in fact. In 1985 , there was a scientist who injected sheep with calcium borogluconate. He reported that ionized calcium decreased.”

Calcium therapy can improve clinical signs, particularly in recumbent cows, but it may not consistently restore the functional calcium pool. This helps explain why some cows respond only temporarily or relapse after treatment.

A Shift in Thinking: Hypocalcemia as Part of Immunity

Ametaj’s work proposes a fundamental shift in how hypocalcemia is interpreted — not simply as a failure of calcium supply, but as part of a broader physiological response.

“Hypocalcemia is important, because it’s not a deficiency, but part of immunity,” Ametaj says. “That’s where the entire new concept starts.”

In this model, calcium dynamics are closely tied to immune activity, particularly during the stress of calving and early lactation.

This model builds on another important shift: transition cows are not immunosuppressed, but are actively responding to inflammatory signals.

“Usually, the dogma is that the cows around calving are immunosuppressed, but in fact, they are mounting an immune response, especially the innate immunity is very active and acute phase response,” Ametaj explains.

Inflammatory markers begin to rise weeks before calving and peak around parturition. Cytokines such as TNF-alpha, interleukin-1 and interleukin-6, along with acute phase proteins, are consistently elevated during this period. Rather than a failure of immunity, this suggests the cow is managing a significant inflammatory load at the same time she is adapting metabolically to lactation.

In the framework of the calci-inflammatory network, bacterial endotoxins from conditions like mastitis or acidosis trigger an inflammatory response that suppresses parathyroid hormone secretion. This cascade ultimately inhibits calcium absorption and bone resorption, leading to hypocalcemia, commonly known as milk fever in cattle.

(Farm Journal)

Endotoxin: A Likely Trigger

One of the proposed drivers of this inflammation is endotoxin, or lipopolysaccharide (LPS), originating from the gastrointestinal tract.

Transition diets high in fermentable carbohydrates can lower rumen pH, disrupt epithelial integrity and increase endotoxin release and absorption. As rumen conditions become more acidic, Gram-negative bacteria break down and release LPS into the rumen environment.

“When you feed different amounts of grain, you increase the amount of endotoxin in the rumen fluid by 18- to 20-fold,” Ametaj says, noting these shifts were also seen in the blood along with changes in cytokines and acute phase proteins.

Once endotoxin enters circulation, it contributes to systemic inflammation, linking nutritional management directly to immune activation. The immune system responds rapidly to endotoxin exposure by activating macrophages and triggering signaling pathways designed to neutralize and remove the threat.

“If macrophages are activated, they release pro-inflammatory cytokines: tumor necrosis factor alpha, interleukin-1, interleukin-6. Why do they do that? Because they invite more cells, immune cells, to come there to remove endotoxin,” Ametaj explains.

This response is essential, but also metabolically demanding. Nutrients and minerals are redirected to support immune function, and physiology shifts to prioritize survival over production.

Calcium as an Active Player in Immunity

Within this framework, calcium is not simply a nutrient to maintain but an active participant in immune function.

One key role is in endotoxin handling. Lipopolysaccharide carries a strong negative charge, allowing calcium to bind and promote aggregation. This clustering makes endotoxin easier for immune cells to recognize and remove.

“Endotoxin is very negatively charged. And calcium binds to molecules of endotoxin and brings them together and creates aggregates,” Ametaj explains.

Endotoxin can also bind to lipoproteins in circulation and be transported to the liver, where it is neutralized and excreted in bile. This process is rapid and tightly regulated, linking inflammatory load to liver function and lipid metabolism.

Together, these pathways suggest calcium is being actively used and redistributed during immune responses, not simply depleted.

Current Strategies

Current approaches to milk fever focus on increasing calcium availability, either through supplementation or dietary strategies, such as DCAD. These tools remain valuable, but they operate within a more complex biological system than previously appreciated.

“By triggering metabolic acidosis, you also trigger elimination of calcium from the blood through urine outside. Why? Because calcium and other cationic ions bind these acids, and they are eliminated,” Ametaj says.

DCAD programs improve calcium mobilization, but they also shift systemic mineral balance. Similarly, calcium therapy can resolve clinical signs without addressing the underlying drivers of inflammation. This may help explain why these strategies work well in some situations but inconsistently in others.

What This Means for Veterinarians and Producers

This evolving perspective does not replace current practices, but it does broaden the approach to prevention.

In addition to managing calcium, attention may need to shift toward upstream factors that influence both inflammation and mineral balance, including:

Maintaining rumen stability and avoiding sharp drops in pH
Managing starch levels and fermentation rates
Supporting gut barrier integrity
Reducing systemic inflammatory load

These areas may offer opportunities to improve consistency in transition cow outcomes.

The immune–calcium network offers a more integrated way to understand milk fever — one that connects metabolism, inflammation and mineral dynamics.

Rather than asking only how to raise calcium status, a more useful question may be: Why is calcium low in the first place?

Answering that question may be key to improving transition cow health and to making existing prevention strategies work more consistently.

To hear more from Ametaj on the immune-calcium network and the management of transition cows to avoid hypocalcemia, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

Genomics and the Evolving Role of the Bovine Veterinarian

Wed, 25 Mar 2026 14:41:40 GMT

Genomic testing is gaining traction in the beef industry, but for many producers, adoption still feels out of reach. The tools are available and the data is powerful, but the starting point is often unclear.

Increasingly, producers are looking to their veterinarians for guidance. The challenge is that many veterinarians are still defining what their role in genomics should look like.

Insights from Dr. Kirk Ramsey, professional services veterinarian, and Kelsey Luebbe, genomics technical services scientist, both with Neogen, highlight both the opportunity and the uncertainty shaping this shift.

An Expanding Role for a Trusted Voice

Producers have no shortage of information about genomics. Industry media, technical specialists and webinars all contribute to awareness, but when it comes time to make decisions, veterinarians remain a trusted source.

That trust is rooted less in genomics expertise and more in long-standing relationships and a deep understanding of herd performance. Veterinarians already play a central role in decision-making on many operations. Genomics is simply extending that role into new territory.

For many practitioners, genomics aligns closely with work they are already doing.

Veterinarians advise on heifer selection, evaluate bulls and track reproductive performance over time. They understand how cattle perform within a specific environment and how past decisions continue to influence current outcomes. This perspective is increasingly valuable as genomic data becomes part of the conversation.

“We have to be very diligent about looking for opportunities to expand our consulting realm because we have to maintain a capacity to provide value to our customers, especially as technology comes on and is moving forward,” Ramsey says.

Rather than focusing solely on treatment and prevention, veterinarians are being pulled into more strategic discussions, helping producers evaluate trade-offs and set long-term direction.

“We have to be on top of understanding what’s out there, understanding how we can provide value, and then at the same time, trying to be more than just the traditional veterinarian that we have always been. Maybe dive in a little bit more and leverage our capacity to understand the production systems and new technologies, helping our customers be progressive.” Ramsey adds.

This adjustment does not replace traditional services, but builds on them.

The Confidence Gap

Despite this opportunity, many veterinarians do not feel fully prepared to lead genomic discussions.

“As a veterinarian, I had no idea that my producers were looking to me for genetic advice. I knew they were looking to me for treatment advice, vaccination protocols or maybe even general production type questions, but I didn’t realize I actually had that much influence over whether they would even look in the genomic direction,” Ramsey says.

There is a growing awareness that expectations have changed, even if training has not fully kept pace.

“We don’t have a ton of training as veterinarians on genomics,” Ramsey begins. “It was a class we took at 6:30 a.m. back in undergrad, but I don’t feel like I learned a lot more in the DVM program.”

At the same time, industry organizations and companies are beginning to expand continuing education and develop resources to support veterinarians in this space.

The knowledge gap exists, but it is narrowing.

(Vernon Bewley - Neogen)

A Practical Entry Point

For veterinarians, stepping into genomics does not require mastering every detail of the technology. It starts with approaching it the same way they approach other herd-level decisions.

“If somebody comes and says, ‘Hey, I want to start testing,’ the first thing is to establish the goals. What are you trying to accomplish? Where are we headed? What are the things that we can help you identify? Where are the hurdles that you currently are facing and how can we help you move past them?” Ramsey says.

1. Start with herd goals, not genomic tests

Genomics is most useful when it is tied to a defined objective. Without that context, even strong data has limited value.

“Sometimes that conversation stalls because ‘What are your goals?’ is such a huge, open-ended question. So we reframe it: Where are you making money? Where are you losing money? Or, where does it really bother you that you’re losing money? That’s where we start,” Luebbe says.

Framing the conversation around economics makes it more actionable.

2. Use what you already know about the herd

Veterinarians bring years of observation and data to the table. Genomics adds another layer, helping explain patterns and refine decisions rather than replacing existing knowledge.

3. Lean on available resources

While genomics-specific training for veterinarians is still developing, practical information is available through industry partners, genomic companies and professional organizations.

4. Focus on interpretation, not promotion

The veterinarian’s value lies in helping producers understand and apply results, not in selling a specific test.

5. Integrate genomics into existing decision points

Genomics fits naturally into decisions already being made, including replacement selection, breeding strategies and long-term planning.

What Getting Started Looks Like for Producers

For producers, the biggest barrier to adoption is often uncertainty, not resistance.

A practical starting point is to focus on a defined group of animals tied to an immediate decision, such as replacement heifers. This allows genomic data to be applied directly without overcomplicating the process. Luebbe suggests making the process fun can be a good entry point.

“Test the animals that you’re arguing about with your brother,” Luebbe says. “Whether it’s the whole bunch, the bottom 50% or the top 25%. Do it so that you can gain some additional information to help you make better decisions.”

Optimally, testing should represent the whole group being evaluated rather than a small subset of top-performing animals, ensuring the results provide a meaningful picture.

Genomics works best alongside visual assessment and experience. It adds insight into differences that are not always visible but does not replace practical knowledge.

The Growing Intersection of Genetics and Health

While genomics has traditionally focused on production and maternal traits, its role is expanding into health.

“We’re starting to bring more health-driven traits to the table. Using genomics to understand the capacity of the immune system for the animal and their genetic risk of developing bovine respiratory disease or congestive heart failure. We’re starting to see this change in the industry and leveraging genomics to understand what health concerns our cattle might be having,” Ramsey says.

This shift strengthens the connection between genomics and veterinary expertise, creating new opportunities to improve herd resilience and reduce disease risk through selection. As these tools evolve, veterinarians will play a key role in helping producers interpret and apply this information effectively.

A Shift Already Underway

Genomics is no longer a future concept. It is a tool that is steadily becoming part of everyday decision making.

“Genomics will never replace a producer’s understanding of their cattle,” Ramsey says. “But what it can do is uncover that layer hidden underneath the skin and identify the genetic capacity that they’re actually bringing.”

For veterinarians, the shift is already happening. Producers are asking questions, expectations are evolving and data is becoming part of routine conversations. The opportunity is not to become an expert in every aspect of genomics, but to build on the role veterinarians already hold.

Getting started does not require having all the answers. It requires stepping into the conversation and helping move it forward.

Tips for Managing Hospital, Chronic and Rail Pens in Beef Feedlots

Fri, 20 Mar 2026 14:43:53 GMT

Special pens are designed to improve outcomes. But in many feedlots, they quietly become a source of drag on both health and performance.

“There’s a lot of philosophy around special pens, and not a lot of science,” says Dr. Brian Warr, veterinarian with TELUS Agriculture. “But the goal is to have as few animals as possible in each pen. We’re trying to keep it a truly special place, somewhere cattle can go and get better.”

In practice, that is not always what happens. Over time, hospital, chronic and rail pens can evolve into a catch-all for anything that does not fit elsewhere. Lame cattle, poor doers, repeat pulls and animals with unclear diagnoses accumulate in the same space. The result is not just inefficiency, it is a loss of structure.

“I see special pens that are like my top dresser drawer, you open it up and it’s just everything I don’t know what to do with,” Warr says. “In my book, if it’s in there, it should have a reason.”

To reclaim efficiency, we must stop viewing these pens as waiting rooms and start seeing them as active decision points. Every hour an animal spends in a special pen should move it toward a defined outcome:

Recovery (Return to home pen)
Reclassification (Move to chronic/salvage)
Euthanasia (Welfare intervention)

By shifting the mindset from storage to movement, veterinarians can turn a source of drag back into a high-performance tool for health.

Start with One Principle: Treat and Go Home

“We treat the animal and then the question becomes, now what?” Warr says. “The philosophy that’s come out of this is ‘treat and go home.’ Once they’re treated, we send them back to their home pen whenever we can.”

This approach challenges a long-standing instinct in feedlot management, which is to hold cattle back for observation after treatment. While that instinct is well intentioned, it often overlooks how strongly the environment influences recovery.

The home pen offers familiarity. Cattle return to known pen mates, an established social hierarchy and consistent access to feed and water. It also helps avoid disruptions in diet, which can be important in high-energy finishing systems.

By contrast, moving cattle into a shared hospital environment introduces what Warr describes as the “hospital effect.”

“When we put all the sick cattle in one place, we’re increasing infectious disease pressure,” he says. “We’re also introducing stress. It’s a new environment, they don’t know where the feed or water is, and the social order has to reset.”

Those stressors influence intake, behavior and immune function in ways that can counteract treatment.

Warr’s field experience comparing treatment protocols has supported this idea. Cattle treated with the same antimicrobial performed better when returned to their home pen than when held in a hospital pen.

This does not mean special pens are unnecessary, but it does mean they should be used selectively, not routinely.

Define the Role of Each Pen

Clarity in special pen management starts with defining what each pen is actually for, and just as importantly, what it is not for.

1. Treatment (Hospital) Pen

The treatment pen is intended for cattle that require active, short-term management. These are animals that need to be brought back through the chute for multiple days of therapy or require close observation due to the severity of their condition.

In many operations, this pen also becomes a holding area for cattle that are “too something”: too sick, too lame or too light to return to their home group. That can be appropriate, but it should be intentional.

The priority is maintaining flow. Every animal in the treatment pen should be moving toward a defined outcome. Some will complete therapy and return to the home pen. Others may transition into the chronic group. A small number may require euthanasia.

2. Chronic Pen

The chronic pen is where management discipline becomes most important — and where it often breaks down.

“When you walk into a chronic pen, you’re looking at the worst cattle in the whole feedlot,” Warr says. “It can feel defeating. But these are a small percentage of the total population, and we need to manage them deliberately instead of losing track of them.”

Without structure, that is exactly what happens.

“The big thing is don’t let it turn into an ‘I don’t know’ pen,” he adds. “If you don’t have a system, cattle just stay there and no one knows where they came from or where they’re going.”

Introducing a simple evaluation system can restore clarity.

“If I walk into that pen today, I might not know if that animal is getting better or worse,” Warr says. “But if I have a weekly data point, like weight, I can make that decision.”

That combination of objective and subjective assessment allows for more consistent decisions. Cattle can return to the home pen if they are improving and able to compete. Others may move to salvage if they are unlikely to finish. Some will require intervention from a welfare standpoint.

3. Rail Pen

The rail pen represents an endpoint in the system, but it still requires active management.

Tracking these outcomes clearly provides feedback on earlier treatment and management decisions. Without that information, it is difficult to evaluate how protocols are performing over time.

From a practical standpoint, this pen requires attention to withdrawal times, fitness for transport and clear entry criteria. These decisions often involve both economic and welfare considerations, so consistency is important.

4. Buller (Rider) Pen

The buller pen is designed to address mounting behavior, but it should remain temporary.

“We’ll give those cattle a cool-down period and then try to send them back,” Warr says. “About a third may come back again, but two-thirds will stay. If we don’t try, we just end up building bigger and bigger buller pens.”

Holding cattle too long in these pens can recreate the same social pressure that caused the issue in the first place. Reintroduction should be the default approach whenever possible.

Redefine the System: From Performance Drags to Biocontainment

The failure of a special pen is rarely complex. It is usually the result of overcrowding, poor footing and inconsistent management. These persistent issues don’t just slow recovery, they can actively create new health crises.

Beyond physical stressors, feeding strategy remains one of the most common blind spots in special pen management.

“When cattle go from a lower-energy hospital ration back to a higher-energy home ration, we can create acidosis,” Warr warns. “The clinical signs can look like a BRD relapse, and then we end up treating something that wasn’t BRD at all.”

This metabolic whiplash can lead additional losses that are difficult to explain on a necropsy report.

Correcting these nutritional gaps is the first step, but the larger opportunity lies in shifting toward a culture of biocontainment. While perfect biosecurity is often an unreachable goal in a feedlot, practical biocontainment — limiting the spread within the yard — is achievable. This shift opens the door to high-impact operational changes: adjusting treatment orders, separating high-risk cases and planning ahead for disease events. In high-performing facilities, this is simply part of the culture: the last animal isn’t out of the chute before the crew is already cleaning the alley.

The Bottom Line

Special pens should improve outcomes, not concentrate problems. For veterinarians and managers, the opportunity is in creating clarity: define the purpose of each pen, set clear movement criteria and build systems crews can follow consistently.

In the end, the goal is to use special pens deliberately — and as little as possible.

A Veterinarian’s Guide to Protecting Your Body in Practice

Tue, 17 Mar 2026 14:15:51 GMT

Large animal practice is physically demanding work. Long days in barns, repetitive movements and awkward positioning can take a toll that many practitioners feel within the first few years of practice.

Dr. Tracy Potter, a recent veterinary graduate working in dairy practice, has already begun thinking carefully about how those physical demands can shape a career.

“And when I was first riding around with veterinarians, I quickly realized that the rate of chronic injuries is super high,” Potter says.

That observation pushed her to think differently about longevity in the profession.

“I really value this body that I was given, and I want to make it last so that I can be a vet for a really long time — but also so that I can enjoy my life outside of being a vet,” Potter says.

Early in her career, she noticed another message circulating among veterinarians: The idea that injuries are almost inevitable.

“I was really encouraged to have a back-up plan and like, ‘Oh, you should really think about doing mixed animal so you can fall back by doing small animal when you get injured.’ And I didn’t really like that answer,” Potter says.

Instead of assuming injury was unavoidable, Potter began focusing on practical ways veterinarians could protect their bodies and extend their careers. Drawing from her early experiences in dairy practice, she outlines several habits that can help reduce strain and support long-term career sustainability.

1. Train Both Arms

One of the simplest strategies for reducing strain is also one many veterinarians overlook: learning to palpate cows with both arms.

Relying exclusively on a dominant arm can place repeated stress on the same muscles and joints, increasing the risk of fatigue and injury. Developing ambidextrous skills allows veterinarians to alternate arms and distribute that workload.

However, training the non-dominant arm requires patience. It took two to three months of work for Potter to feel like her non-dominant arm was useful, and six months for her to feel like it was as good as her dominant arm.

“These muscles that you use for palpating take a really long time to grow. They’re really small muscles, and they are really prone to injury,” Potter says.

Gradual progression is key. Starting with easier examinations and slowly building toward more demanding palpation work allows those muscles to develop safely.

Over time, alternating arms between cows can reduce fatigue during long palpation sessions while helping protect against overuse injuries.

2. Improve Palpation Ergonomics

Body positioning and technique also play a major role in preventing strain.

One important factor is leverage. When palpating, a veterinarian’s shoulder should ideally be positioned above the cow’s rectum. That alignment allows larger muscle groups in the shoulder and back to contribute to the movement rather than forcing smaller arm muscles to do all the work.

“This is just physics. You can get a lot better leverage when your shoulder is above the cow’s rectum,” Potter says.

Achieving that position often requires using a stool, particularly when working with taller cows. Some practitioners hesitate to do so, but avoiding it can lead to unnecessary strain.

“Get your ego in check and just get a stool,” Potter says.

While it may seem like a small adjustment, proper positioning can significantly reduce stress on the shoulder, wrist and back during repetitive procedures.

Potter also stressed the importance of protecting your shoulder joint while entering and exiting a cow.

“Instead of just ripping your arm out of the cow, I always think about retracting my shoulder blade down my back first. That protects your joint,” says Potter.

3. Train Like an Athlete

Another key lesson Potter emphasizes is that the work itself should not be considered sufficient physical conditioning.

“Speaking of strength training, our job is not strength training,” Potter says. “I think about it like we’re athletes.”

Athletes train deliberately to prepare their bodies for the stresses of competition. Veterinary professionals, she says, should think about their physical preparation in the same way.

“You can’t imagine a professional soccer player saying ‘I don’t need to train. I just go to the game and that’s my workout,’” Potter says.

Regular strength training — even just a few sessions each week — can help veterinarians build the stability and resilience needed to handle the physical demands of practice.

The goal is not perfection but consistency. Even short workouts can make a difference when maintained over time.

4. Make Expertise the Priority

Protecting the body also means thinking about the long-term shape of a veterinary career.

Procedures such as pregnancy diagnosis will always be a core part of dairy practice, but many veterinarians are also developing consulting and advisory roles that rely more heavily on expertise than physical labor.

“Make your brain more valuable than your arms,” Potter says.

Services such as employee training, milk quality consulting, nutrition management and on-farm research can expand the value veterinarians bring to clients while reducing the amount of repetitive physical work required.

Building a sustainable career

Dairy practice will always involve physical work. But injury does not have to be accepted as an inevitable part of the profession.

Potter’s advice reflects lessons learned early in practice: small habits and deliberate preparation can help veterinarians protect their bodies while building careers that last.

Is Bovine Leukemia Virus Hiding on Your Dairy?

Fri, 06 Mar 2026 15:07:52 GMT

Bovine leukemia virus (BLV) is present in most U.S. dairy herds, but many producers do not know it. Because infected animals often appear healthy, the virus can circulate quietly for years before its impact becomes visible.

“BLV is often present long before it becomes an issue. So, if you’re not looking for it on the farm, chances are it’s there, but if you’re not looking, you don’t know or you don’t see it,” Tasia Kendrick, associate professor at Michigan State University, says on a recent episode of “The Dairy Health Blackbelt Podcast.”

Kendrick studies BLV epidemiology and control strategies in dairy herds.

That quiet presence can make BLV difficult to recognize. On many farms, the infection only becomes visible after production or health problems begin to accumulate.

“I’ve talked to quite a few producers, and it’s not a problem until it is. And then, all of a sudden, the animals dying are condemned at slaughter. It’s too late to do anything about when we get to that point,” Kendrick says.

BLV at a Glance:

Present in 80% to 90% of U.S. dairy herds
Up to 40% to 50% of animals infected within affected herds
Impacts immune function, longevity and production
Spreads primarily through blood-to-blood transfer

Subclinical Production and Immune Effects of BLV

Part of the challenge with BLV is that infected animals often appear normal during daily observation. However, research increasingly shows the virus can affect multiple aspects of herd performance.

“Those animals may appear to be normal, but you may be treating them for other ailments through their entire life, and then they leave the herd early, which leads to profit loss for that producer,” Kendrick says.

The economic impact often comes from small performance losses that accumulate across the herd. Reduced milk production, shorter productive lifespans and additional health treatments can all contribute to lower overall profitability.

The virus affects the immune system directly, which can influence both disease resistance and vaccine response.

“The way the virus works is it lays latent in the immune system. It targets B cells, one of your immune cells, and it can lay latent and dormant until it doesn’t,” Kendrick says.

Because BLV infects immune cells, affected animals may be more susceptible to secondary diseases or respond less efficiently to vaccination programs. Over time, those subtle effects can reduce both longevity and productivity.

How BLV Spreads on Farms

Understanding transmission is central to controlling the virus. BLV spreads primarily through the transfer of infected blood between animals.

“The virus itself targets B cells, which are just cells of the immune system that are in the blood system. So it’s a blood-to-blood transfer that moves it from animal to animal,” Kendrick says.

Routine management procedures can inadvertently contribute to transmission if proper precautions are not taken. Shared needles, contaminated equipment or procedures that transfer even very small amounts of blood between animals can spread the virus.

Vertical transmission is also possible.

“The virus is small enough that it can go through the placenta wall, so there is some dam-to-calf transfer as well as colostrum,” Kendrick says. “If raw colostrum or milk is fed, there’s potential for live virus to infect the animal that way.”

These pathways mean infections can occur both in the milking herd and during early life stages.

Practical Management of BLV

Because dairy operations differ widely in their management practices, BLV control strategies often need to be tailored to individual farms.

“It’s not one solution for every farm because every farm is managing their animals differently from colostrum all the way up to the milking herd,” Kendrick says.

Still, several practical steps can help reduce transmission risk.

“It’s really thinking about management strategies of what you can do to reduce blood-to-blood transfer, whether that’s single-use needles, single-use sleeves, fly control, anything that’s going to decrease the chances of blood transfer,” Kendrick says.

Key Strategies to Reduce BLV Transmission

1. Reduce blood transfer.

Use single-use needles.
Use new palpation sleeves for each cow.
Maintain strict hygiene during procedures.

2. Manage colostrum carefully.

Avoid feeding raw pooled colostrum.
Freeze or pasteurize colostrum when possible.

3. Control biting flies.

4. Establish herd status through targeted testing.

Testing every animal may not be necessary to understand the scope of infection.

“If you test 40 specific animals across the lactation in your herd, you get a pretty good picture of the prevalence, so you have a starting point and you don’t have to test every animal in your herd,” Kendrick says.

The Michigan State University BLV website recommends testing the 10 most recently calved cows that are greater than three days in milk from each lactation group (first, second, third and fourth-plus).

Looking More Closely

BLV has circulated in the dairy industry for decades, often without drawing much attention, but growing evidence of its effects on immunity, productivity and longevity is prompting veterinarians and producers to take a closer look.

For many herds, the first step is simply recognizing the virus may already be present.

Precision Genomics: The Veterinarian’s Role in Commercial Herd Rebuilding

Tue, 03 Mar 2026 18:38:02 GMT

With the U.S. beef herd at historic lows , rebuilding is no longer just about numbers. It is about keeping the right females. Today, every retained replacement heifer represents years of genetic influence, input costs and production risk. For the bovine practitioner, this is an opportunity to move beyond traditional “chute-side technician” roles and become a strategic data consultant. Selection is no longer just about phenotype; it is about mitigating biological and economic risks.

The following strategies for precision genomics are pulled from a deep-dive discussion with Dr. Kent Andersen and Dr. Tom Short on The Bovine Vet Podcast . By pairing clinical experience with genomic tools, practitioners can better navigate the current rebuilding phase.

Moving Beyond Visual Appraisal

Visual selection remains a cornerstone of cattle management. Structural soundness, disposition and obvious developmental concerns cannot be ignored. However, phenotype alone does not tell the whole story of an animal’s future productivity.

The Trap of Size: Selecting the largest heifers often inadvertently selects for higher maintenance requirements and increased feed intake.

“Traditionally, commercial cow-calf producers have selected their replacement heifers based on visual appraisal — and perhaps, the ones that are born earliest and just have the look of making a good cow,” says Andersen, director of global beef genetic technical services for Zoetis Animal Health. “Unfortunately, when you select based on looks and size, sometimes you’re picking the biggest ones. So, you’re picking the heifers that may turn out to be the bigger cows that have higher maintenance requirements.”

The Genomic Advantage: Genetic predictions provide insight into metabolic efficiency, fertility, and longevity before a single dollar is spent on development.

“There’s a lot of traits in the unseen world, such as cow fertility, intake, feed conversion, bovine respiratory disease health, that you really can’t gauge by just looking at them,” Andersen says. “The new tools allow the producer to pick heifers that are less risky of dropping out early and maybe not being very profitable.”

Clinical Genomics: Disease Risk and Wellness

One of the more significant recent advancements is the ability to generate genomic predictions related to disease risk, particularly bovine respiratory disease (BRD). Developing those metrics required assembling large populations of cattle with detailed health records and corresponding genotypes. Understanding the value of those predictions requires a clear understanding of heritability.

Heritability vs. Management: Genetics do not replace vaccinations, but they lower the baseline risk. Selecting for higher “Wellness” scores builds a more resilient herd that responds better to clinical protocols.

“Heritability is kind of a term a lot of people don’t understand in a way, but it’s basically just the amount of variation in a trait that we see that’s due to additive genetics, meaning that we can measure it, select for it and improve it,” says Short, associate director in outcomes research with Zoetis Animal Health.

The Data Gap: Historically, commercial heifers lacked the Expected Progeny Differences (EPDs) available to seedstock. Genomic testing (e.g., Inherit Select) bridges this gap, providing EPD-level accuracy on unproven females.

“With this technology, we’re getting genetic predictions in commercial cattle that, if you think about it historically, have had very little, if any, information recorded on them,” Short says. “All the data recording and genetic selection and prediction and everything has really occurred at the seedstock level.”

By combining DNA information with national cattle evaluation systems, commercial heifers can now receive EPDs across a range of economically important traits, from fertility and growth to structural and health-related measures.

Managing Genetic Antagonisms

Selecting for a single trait, such as extreme growth, often comes at a cost to others, such as calving ease or fertility.

“Selecting to increase one trait may actually decrease another, but in an undesirable direction,” Short explains. “That’s where you have to weigh the two traits in an index appropriately, knowing that there’s antagonisms there.”

Economic Indices: Use weighted indices to manage these trade-offs. These tools balance production and maternal performance to ensure overall operation profitability rather than chasing outlier data points.

Precision Culling: Identifying “bottom-tier” genetics early allows producers to divert resources toward high-potential females, optimizing the client’s input costs and long-term sustainability.

The DVM as the “Trusted Adviser”

The veterinarian is often the most influential voice in a producer’s decision-making process, making them the ideal conduit for genomic integration.

“In our interactions with commercial cow-calf producers, it’s almost always the veterinarian that is the most trusted adviser,” Andersen says. “The veterinarian is helping them with their herd health program, so we think it’s a natural fit for the bovine practitioner to also assist with getting DNA collected and using the results.”

Short echoes that sentiment. “Most cow-calf herds that have a valid client-patient relationship with their veterinarian trust them as a resource, and especially when it comes to things like health and genetics, which are more technical aspects of what they have to do in their everyday jobs,” he says.

Workflow Integration: DNA collection via ear punch is easily integrated into routine pregnancy diagnosis, vaccination, or breeding soundness exams.

Consultative Value: By interpreting genomic results, veterinarians can guide mating strategies and marketing decisions—such as selling “value-added” replacements—strengthening the Veterinarian-Client-Patient Relationship (VCPR).

The Economic Reality of Genomic Testing

Early adopters in the commercial space are capturing disproportionate value in a tight market.

“Early adopters are the ones that get the biggest reward,“ Short says. “Not only am I going to select the very best heifers I test for my own replacements, I’ve got a next group here that are pretty good. I’m going to sell them as value-added replacements to my neighbors.”

Genomic testing, often costing between $15 and $40 per head, can lead to significantly higher lifetime returns by ensuring only the most efficient, fertile, and healthy females enter the breeding herd. While visual appraisal and experience are still important, pairing intuition with genomic insight defines the next generation of decision-making.

Summary for the Practitioner

“I think the sail has been set to evolve from real group herd-based to more individual animal-based in our selections, in our matings, in our management protocols, in our days on feed and harvest time protocols,” Andersen concludes. “The individual animal information, I think, paves the way for that.”

As the industry shifts toward individual animal management, genomic data is the next essential “diagnostic tool.” It allows the practitioner to move from managing groups to optimizing individuals, ultimately building a more profitable operation for the client.

To hear more from Andersen and Short on how genomics is redefining the commercial cow-calf industry, including more information on Inherit Select and the newly introduced BRD selection indices, listen to the full conversation on the latest episode of The Bovine Vet Podcast .

Assessing the Off-Feed Dairy Cow

Thu, 26 Feb 2026 19:00:17 GMT

The Consultant diagnostic support system for veterinary medicine lists 363 differentials for the off-feed cow. That number is a reminder that appetite loss is common and rarely simple.

Jessica McArt, professor and department chair at the Cornell University College of Veterinary Medicine, recommends using a disciplined approach to determine the reason why a cow isn’t eating.

In many herds, rumination data provides the first clue. As McArt describes, “You can see this cow has been ruminating anywhere from 500-550 minutes a day, and then over the last 24 hours has dropped pretty dramatically down to 100 minutes. That’s a sure sign that something’s wrong with her rumen.”

This drop tells you that something has changed, but it doesn’t tell you why.

Perform a Thorough Physical Exam

Before treating the rumen, determine whether the rumen is the primary problem. This involves performing a complete physical examination.

“Our goal with this exam is to determine if being off feed is your primary sign,” McArt says. “So, she may otherwise look OK, but the rumen is not moving well. Or is it secondary to a different issue?”

A displaced abomasum, metritis, mastitis, lameness or systemic disease can all reduce intake. Appetite loss is often the consequence, not the cause. A physical exam is non-negotiable. Only once secondary causes are ruled out should you narrow your focus to primary gastrointestinal dysfunction.

Listen to the Rumen

When the rumen is the likely source of issue, spend time with it. McArt advises listening to rumen sounds for a whole minute.

“We want to hear somewhere between one to three contractions,” she says. “These rumens can be hypomotile, or they can be hypermotile where you kind of hear this rumbling the whole time, but they’re not good and strong rumen contractions.”

Hypomotile rumens lack strength and frequency, while hypermotile rumens may produce continuous low rumbling without effective mixing. Neither pattern supports efficient fermentation.

Palpate rumen fill and assess fiber mat integrity. On a rectal exam, look for diarrhea or undigested fiber that suggests fermentation breakdown. These findings will help confirm whether you’re dealing with primary rumen dysfunction.

Consider Stage of Production

“You need to check the stage of lactation and how much milk she’s making,” McArt says. “If you see a cow and she’s 450 days in milk and she’s been making 30-35 lb., you would be like, ‘Well, that seems about right in that pattern.’”

Contrast that with a fresh cow scenario: “If the cow is 13 days in milk and she was making a lot of milk a couple days before, something is obviously wrong with her,” McArt says.

The severity and urgency change with physiology. Earlier lactation cows have less margin for error.

Assess Hydration

Not every off-feed cow is dehydrated, but many are mildly so.

“These cows, some of them are going to be dehydrated, some of them are not. So, we can see variations in skin tent. They may have sunken eyes; they may not,” McArt says.

Skin tent, globe position and mucous membrane moisture can provide clues. Mild dehydration may respond to oral fluids, but more marked dehydration requires more aggressive correction.

Support the Rumen

It would be great to have an ideal drench formula, but McArt comes with bad news: “I will tell you, I did a lot of research, I read a lot of papers. And the answer is nobody knows.”

This doesn’t mean that composition is irrelevant. Calcium, magnesium, phosphorus and sodium all support rumen function. Pairing these minerals with an energy source, such as calcium propionate, can be beneficial to the cow. Notably, phosphorus is often absent from commercial products, but is very important for energy metabolism and rumen fermentation.

The temperature of the oral drench is also critical.

“If you take cold water out of your house and you pump it into that rumen, those bacteria are not going to be happy, and you’re probably going to make the situation worse until she heats that back up,” McArt notes.

Rumen microbes function within a narrow temperature range. Warm water protects fermentation.

Consider Transfaunation

When fermentation has stalled, transfaunation, the therapeutic transfer of rumen fluid, may help.

“It’s been shown that transfaunation can be effective when giving as little as one liter into a cow,” McArt says.

Small volumes can improve rumen function compared with water alone. For farms with an accessible donor cow, transfaunation is a practical adjunct.

Offer Hay

Do not overlook simple mechanical stimulation.

“Studies have shown that if you offer cows that have indigestion some sort of long-fiber hay, they prefer to eat it and recover quicker,” McArt says.

High-quality long-stem hay can help reestablish rumen mixing and stimulate cud chewing. For some cows, this is enough to restart the system.

Be Mindful of a Larger Issue

If off-feed cows start appearing frequently, the conversation needs to widen beyond individual treatment protocols. Recurrent rumen dysfunction may signal ration inconsistency, bunk management problems, feed sorting or mycotoxin pressure .

“If you see this a lot, this is a great place where we can get engaged on the herd level in addition to the cow level,” McArt advises.

The off-feed cow may be an early warning signal for a larger management issue.

9 Questions to Guide Antimicrobial Selection in Cattle

Tue, 24 Feb 2026 19:11:39 GMT

In bovine practice, smarter antimicrobial selection starts by asking better questions. Antimicrobial stewardship isn’t necessarily about using fewer drugs, but using the right drugs for the situation. Dr. Corale Dorn, owner of Dells Veterinary Services in South Dakota, suggests asking the following nine questions before reaching for a bottle.

1. What Pathogens Are We Treating?

“You’ve got to get the diagnosis right before you pick what antibiotic you’re going to use,” Dorn says.

Antimicrobial selection in cattle must begin with pathogen clarity.

Is this truly bacterial disease? And if so, what are the most likely pathogens? A navel infection differs from respiratory disease just as uterine pathogens differ from central nervous system pathogens.

“We’re super lucky that people will bring the sick animals to us … so we have the opportunity to do a very thorough physical exam,” Dorn says. “We want to get that diagnosis right, or at least a good list of differentials, and we’re thinking about some of those comorbidities.”

Before selecting an antimicrobial, narrow your differentials and identify the organisms you are most likely targeting. Stewardship starts here.

2. Is There Something Labeled We Can Use?

Start with labeled products whenever possible.

Is there an antimicrobial approved for this disease in this species? Labeled use strengthens regulatory compliance and simplifies withdrawal considerations. Extra-label drug use may be necessary, but it should follow a clear rationale, be well documented and be founded on a valid veterinarian-client-patient relationship.

3. Is There Any Medication We Cannot Use?

Antimicrobial selection is as much about exclusion as it is about selection.

Are there legal restrictions? Are certain drugs prohibited in food animals? Do extra-label drug use regulations eliminate certain options?

Removing inappropriate options early protects both the patient and practitioner.

4. Can We Reach the Pathogen Where It’s Living With This Drug?

Pharmacokinetics and tissue penetration should drive decisions.

“There’s lots of things out there that are labeled for Histophilus somni in cattle to treat it. However, if it’s in the brain and it’s causing TEM, is that drug going to be able to penetrate through the meninges?” Dorn asks.

Drug labels and spectrum charts are helpful, but drug distribution determines success. Lung tissue, uterus and central nervous system each present different barriers.

Dorn explains often the question posed is whether bacteriostatic or bactericidal antibacterials are better. In the past, students were taught bactericidal was best, but recent work suggests that it doesn’t really make a difference.

“Can that drug get to that location is more important,” Dorn says. “It doesn’t really make a difference whether it’s static or cidal as long as we’re giving support to the animal.”

5. Can We Even Get That Product Right Now?

Dorn has an all too familiar question she has to ask: “Is it even on the shelf this week?”

Ideal protocols mean little if the drug is unavailable.

“The supply chain business is just infuriating. You get it down to your favorite protocols, and then that’s not available anymore,” Dorn says.

Drug shortages and supply variability have become part of production medicine. Understanding drug classes and alternatives allows flexibility when inventory shifts.

6. What Are the Milk and Meat Withdrawals?

Withdrawal times are central to antimicrobial use in cattle.

How long are milk and meat withdrawals? Does this animal’s stage of production make those intervals critical? Is she close to market? Is she a high-producing dairy cow?

Withdrawal considerations affect economic decisions and regulatory compliance.

7. How Many Treatments and How Easy Is the Treatment?

“You’re thinking about how many treatments this is going to take and how easy it is to give the treatments in this particular case,” Dorn says, acknowledging each operation is different. Daily restraint in a well-designed dairy parlor differs dramatically from catching pasture cows multiple times.

Communicating the impact of the individual operation with your client is also important.

“It never fails,” Dorn says. “You give a treatment, and they say, ‘Oh, that’s not what you gave my neighbor’s cow last week.’”

Treatment protocols must fit the production system, not just the pathogen.

8. How Much Does It Cost?

Drug choice influences not only treatment success but also labor costs, compliance and client perception.

“You will build relationships with your clients by kind of walking through the thought process and letting them decide they’d rather spend more money and not have to treat her [again] versus just complain that you always pick the most expensive antibiotic when you get there,” Dorn explains.

Transparency strengthens trust and structured reasoning builds credibility.

9. How Does This Fit Antimicrobial Stewardship?

Every antimicrobial choice contributes to the broader stewardship landscape.

“Make sure that we protect those antibiotics that we want to be able to use,” Dorn says, praising the work AABP has done to ensure antimicrobial availability. “In order for all of us to be able to do this for generations to come, you have to think about this.”

Responsible antibiotic use in cattle requires:

Confirming bacterial disease
Targeting pathogens where they reside
Choosing appropriate, reachable drugs
Considering withdrawals
Evaluating practicality and cost
Preventing recurrence through management

Veterinary antimicrobial stewardship protects drug efficacy for future herds and future generations.

The Bottom Line

Antimicrobial selection in cattle is not about memorizing a gold standard drug. It is about systematically answering the practical questions.

“It’s not one gold standard,” Dorn says. “It is a continuum and it’s going to be tailored to the situation that’s in front of you. You need to take a look at the whole picture from the client and then come up with a best agreed-upon treatment plan.”

Taking a pause to consider the whole picture could be the most important step in making sound antimicrobial decisions.

4 Tips for Assessing Hydration Status in Calves

Fri, 20 Feb 2026 14:56:39 GMT

Assessing dehydration status is the first step in managing a scouring calf, but it’s not as simple as assigning a percentage. Dehydration, acidemia and neurologic function do not progress at the same rate. A calf may not look profoundly dehydrated but still require intravenous correction.

Speaking at the AABP Recent Grad conference, Dr. Blake Balog, professional services veterinarian with TELUS Agriculture, outlined some tips for assessing hydration status in calves.

1. Start with the Eye

Globe recession remains one of the most reliable field indicators of dehydration, but only if it is measured correctly.

Balog recommends rolling down the lower eyelid to look for space.

“Make sure when you’re assessing that you’re rolling that lower eyelid out to a more normal position and measure that depth,” Balog says. “If it’s hitting somewhere in the 4 mm range, that’s going to be close to 8% dehydration, which is the point where we want to use IV fluids.”

Measure deliberately and determine whether oral fluids will be enough.

2. Check Peripheral Profusion

As dehydration progresses, circulation shifts centrally and causes the extremities to cool. While you could invest in an infrared thermometer, using your hands to feel whether the peripheral distal limbs are cold or cool will likely suffice.

Cold limbs alone may not indicate dehydration, but they certainly reinforce that it may be the case.

3. Separate Dehydration from Acidemia

“The level of dehydration doesn’t always linearly go along with the level of acidemia,” Balog says.

This is a crossroads at which decisions can go wrong. A calf may not appear severely dehydrated and still be acidemic. Relying on percent dehydration alone can miss calves that require escalation.

Balog suggests testing the palpebral reflex.

“When you tap that medial canthus and you get a delayed or sluggish palpebral reflex, that’s an indicator of lactic acid that’s accumulated in that animal,” Balog says.

Delayed reflexes, weakness and failure to suckle suggest metabolic compromise. If the calf cannot suckle, oral therapy alone is unlikely to be enough.

4. Use Supporting Findings

Urine concentration can reinforce your assessment. If a refractometer is available, specific gravity could be used. Otherwise, dark, concentrated urine supports systemic dehydration.

Skin tenting is another quick way to evaluate hydration. Pinch a fold of skin on the neck or around the eyes and count the number of seconds it takes to flatten. Skin flattening in less than 2 seconds indicates normal hydration, 2 to 5 seconds to flatten indicates 8% dehydration and over five seconds would indicate severe dehydration over 10%.

Placing an IV Catheter in Calves

Placing an IV catheter in a dehydrated calf can be more difficult because the skin is thick and the jugular vein does not present well.

Balog recommends focusing on mechanics.

Position the head on a downward slope.
“We’re going to have the head of that calf dropping downward. That’s going to help fill the jugular vein a little bit easier,” Balog says.

Lowering the head improves venous fill and simplifies placement.
Clip and prep generously.
Dehydrated skin offers more resistance. A wide clip and thorough prep make catheter passage smoother.
Perform a cut down incision.
“This is the key part that I think we’ll struggle with: Not doing a cut down. Cut down to me is not sawing with the scalpel blade down toward the jugular. We’re going to tent the skin up and we’re going to go straight down with our 22 blade until it finally releases through there and then we’re going to lay that down,” Balog says.

This incision is vertical and controlled, not a sweeping motion toward the vein. This is critical in dehydrated calves when the skin is super thick and difficult to get through.
Secure the catheter carefully.
Tape and suture so access remains stable during fluid delivery. Balog likes to use a butterfly catheter secured with a couple sutures. He’ll then do an additional suture up on the head so the line remains straight.

The goal is straightforward: assess accurately and intervene appropriately. When dehydration approaches 8% or acidemia affects function, oral therapy may not be sufficient. At that point, gain access, deliver fluids and reassess.

Is Your Dystocia Kit Ready?

Thu, 19 Feb 2026 15:11:35 GMT

Calving season rarely unravels because of one catastrophic mistake. More often, it is delayed recognition, repeated unproductive pulling or the one missing tool that turns a manageable dystocia into a wreck.

A ready dystocia kit is not just a bucket of equipment sitting in the barn office. It is timing, facilities and a clear decision tree that guides what happens when progress stalls. Caitlin Wiley, clinical associate professor at Iowa State University, outlines what you should consider including in your dystocia toolkit.

Start With Time, Not Tools

Before a chain ever goes on a leg, producers and veterinarians should share clear expectations about how long is too long.

Stage one of calving, the initiation of labor through the appearance of the water bag, lasting more than 12 hours warrants concern. Stage two, when the calf should be delivered, extending beyond an hour, and certainly two hours, should prompt intervention.

Wiley advises regular check-ins to ensure things are on track.

“Give yourself 15 to 20 minutes of doing whatever you’re attempting to do. Are we making progress? If not, reassess. If we’re not making progress, what’s our next best step?” she says.

Repeated traction without advancement is not persistence. It is lost opportunity, and often escalating trauma. Clear timing protocols belong in your kit just as much as chains and lubricant, because they determine when you change course rather than double down.

Build a Kit That Extends Your Reach

A functional dystocia kit should be assembled and inspected in preparation for calving.

These are the items Wiley recommends keeping in your kit:

Multiple long OB chains
A wire introducer for placing chains in deep or awkward cases
A head snare or extra chain that can function as one
A calf jack for controlled traction
Ample lubricant, preferably carboxymethyl cellulose based
Suturing material in case of hemorrhage
An oro-gastric tube and a separate stomach tube
A stomach pump
Appropriate drugs, including epidural agents and uterine relaxants
A speculum
A halter for improved restraint

This list is not exhaustive, and individual practice style will shape it further. The key principle is simple: your tools should extend your reach and options, not limit them because something essential was forgotten.

Facilities Are Part of the Kit

Equipment cannot compensate for poor setup. Facilities shape outcomes long before traction begins.

An open-sided chute that allows access from both sides improves both efficiency and safety. A halter tied forward can help prevent repeated setbacks when cows attempt to lie down mid-manipulation. Small adjustments in positioning and restraint often reduce the physical strain on both the cow and the person assisting.

When facilities allow you to evaluate, reposition and reassess without chaos, decision-making improves.

Confirm the Three Ps Before You Pull

Before committing to sustained traction, slow down long enough to confirm your three Ps.

“Position, posture, presentation,” Wiley says. “If you miss those pieces, you can spend a lot of time trying to pull something that’s not going to work.”

Engage the legs into the pelvis before applying force. If you cannot fit your hand between the calf and the pelvis, that observation matters. Continuing to crank without engagement increases trauma and fatigue and rarely improves the outcome.

Backward calves, twins and head-back presentations each demand deliberate assessment before force is applied. In many cases, the decision to pivot starts with recognizing engagement is not happening.

Know When to Change the Plan

There is a point where traction becomes counterproductive.

“I think sometimes we look at C-sections as a fail, and I argue it’s not. It’s a good, valid option. Sometimes the sooner decision becomes the better outcome we have for our cows and our calves,” Wiley says.

The goal is not to prove you can get a calf out vaginally. The goal is viability and recovery.

Changing the plan is not an admission of defeat. It is clinical judgment.

Debrief Every Case

After each dystocia, take time to reflect on what happened, even briefly.

“Regardless of how it comes out, ask, ‘Can we do something different? Can we work on this?’” Wiley suggests.

Was the call delayed? Were timing expectations unclear? Was there a moment when reassessment should have come sooner?

Dystocia will always be part of cattle practice. But incomplete kits, delayed reassessment and reluctance to pivot do not have to be. A ready kit is preparation in both equipment and judgment, and both matter when minutes count.

The Role of Timing in BRD Retreatment Decisions

Thu, 12 Feb 2026 23:29:01 GMT

Retreatment decisions for bovine respiratory disease (BRD) are often made when animals fail to rebound as quickly as expected. A calf still looks depressed, a temperature remains elevated, or animal handlers question whether the initial therapy worked. In those moments, retreatment can feel like the safest option, but evidence suggests when cattle are eligible for retreatment can be just as important as what antimicrobials are used.

Post-treatment interval (PTI) refers to the amount of time that should pass after antimicrobial administration before an animal is eligible for another treatment. It’s not about delaying care arbitrarily, but about allowing drugs time to do what they are designed to do before concluding that further intervention is required.

“We have very high-quality medications and sometimes we need to let those drugs have enough time to work,” explains Dr. D.L. Step, senior professional services veterinarian at Boehringer Ingelheim. “By allowing that period of time, we don’t have to stress the animals by getting them up into a chute to be further evaluated for more treatment.”

PTI is a Clinical Decision

PTI is a question of timing. Once an animal meets a BRD case definition and receives antimicrobial therapy, clinicians must decide how long to wait before reassessing and potentially retreating. That decision is often influenced by clinical appearance and management pressure rather than pharmacologic behavior.

This raises the question: If retreatment happens too soon, are cattle actually failing therapy, or are they still in the expected window of recovery?

To examine that question, a 2020 field study evaluated PTIs following treatment with gamithromycin in cattle with naturally occurring BRD. Animals were assigned to retreatment eligibility at three, six, nine or 12 days.

The results revealed a clear pattern. Cattle eligible for retreatment at three days had higher retreatment rates. At the opposite extreme, cattle held to a 12-day PTI experienced poorer final outcomes, including higher case fatalities. The most favorable outcomes in this study occurred when retreatment eligibility fell between six and nine days.

These results suggest there is both a lower and an upper boundary for effective PTI, at least for gamithromycin.

These results are grounded in how gamithromycin behaves in the animal.

“Gamithromycin can stay in alveolar macrophages that fight infection down in the lung,” Step says. “We know the drug can stay there for up to 10 days.”

This persistence provides a biologic explanation for the observed outcomes. Retreatment at three days may occur before the drug has completed its therapeutic effect. Extending PTI too long, however, may delay intervention in animals that need further evaluation, which may explain the different outcomes at 12 days.

Handling stress may also be a contributing factor. Earlier retreatment requires pulling recovering cattle back through the chute, which may further compromise recovery.

When PTI did not change outcomes

Not all antimicrobials behave the same way. A more recent multisite study from Kansas State University evaluated PTIs following pradofloxacin treatment for BRD in stocker cattle. In that work, cattle were assigned to retreatment eligibility at three, six or nine days and followed for 45 days.

Within this range, no statistically significant differences were detected in the first treatment success, case fatality or days to death among PTI groups. Unlike the gamithromycin study, PTIs beyond nine days were not evaluated, so the effect of extended intervals could not be assessed.

The pradofloxacin findings reinforce an important point: PTI effects are drug-specific. These results do not mean that PTI timing is irrelevant, rather that no effect was detected under the conditions of this study.

PTI and Antimicrobial Stewardship

PTI is a stewardship issue grounded in outcomes, not restriction. In the gamithromycin study, shorter PTIs resulted in more antimicrobial use without improved performance. Allowing appropriate time between treatments reduced retreatment frequency and improved outcomes.

“If you wait a little bit longer, the outcomes are better and you don’t use as many drugs,” Step says.

This approach aligns stewardship with clinical effectiveness rather than limiting access to therapy.

What this Means for BRD Protocols

The practical takeaway is not a single retreatment day, but rather the opportunity for a retreatment window that reflects drug characteristics, cattle type and management conditions.

“A veterinarian can prescribe and say, ‘Maybe we wait seven or eight or nine days,’” Step says.

PTI should be considered alongside antimicrobial selection and case definition rigor.

By evaluating each case in context and adjusting protocols based on observed outcomes, PTI deserves the same level of attention as any other component of BRD treatment decision-making.

Cattle Injection Guide: Best Practices for Needles, Syringes and Sites

Wed, 11 Feb 2026 19:58:35 GMT

Proper injection technique is a cornerstone of Beef Quality Assurance (BQA). Dr. Dan Thomson, Production Animal Consultation (PAC) veterinarian, recently shared expert insights on “ DocTalk ” regarding how to perform “ordinary tasks extraordinarily well” to ensure animal health and carcass quality.

What are the three types of cattle injections?

There are three primary methods for administering medicine to cattle. Following label instructions is critical, as changing the method — moving from SubQ to IM — can alter FDA-approved withdrawal times.

Subcutaneous (SubQ): The most common method. Medicine is deposited between the skin and the muscle lining. BQA limit: No more than 10 cc per site.
Intramuscular (IM): The injection goes through the skin directly into the muscle.
Intravenous (IV): Medicine is injected directly into the bloodstream, usually via the jugular vein.

Needle Selection Chart: Gauge and Length

The correct needle size depends on the administration method and the weight of the animal. A smaller needle reduces pain but limits the volume of fluid that can be pushed quickly.

Injection Type	Needle Gauge	Needle Length
Subcutaneous (SubQ)	18-16 gauge	0.5 to 0.75 inch
Intramuscular (IM)	20-16 gauge	0.75 to 1.0 inch
Intravenous (IV)	18-14 gauge	1.0 to 1.5 inch

“Obviously, the smaller the needle, the less pain, but the less volume that can be pushed through at one time,” Thomson explains.

Where is the best injection site for cattle?

According to Thomson, to protect high-value meat cuts, all injections should be given in the “injection triangle” on the animal’s neck. This area is bordered by the nuchal ligament, the neck vertebrae and the slope of the shoulder.

IM Technique: Administer the needle perpendicular to the neck.
SubQ Technique: Administer at a 45-degree angle.

“Before I inject, I always move the syringe to make sure it’s at that subcutaneous spot,” Thomson advises. “If I have caught the fascia or if I’ve caught that muscle, the end of the needle won’t move. But if it’s under the skin and it wiggles a little, I can be assured that I’m in the SubQ area.”

Safety and Hygiene Rules

The 10-Head Rule: Change needles every 10 injections to prevent causing cattle pain from burred needles tearing the hide.
“If I give five to one animal in a 50 mL administration, I’m only going to work on two animals before I change that needle,” Thomson explains.
No Tenting: Use a one-handed technique for SubQ injections. Do not “tent” the skin with your free hand to avoid accidental self-injection.
Zero Contamination: Never put a used needle back into a multidose bottle. This prevents manure and bacteria from contaminating the entire supply.
Thomson explains a new needle or disposable syringe should be used to draw the product to not contaminate the bottle, even when it is an antibiotic. Injection site abscesses can come from even the smallest speck of manure contaminating a medicine bottle.
The “Faster” Myth: Research shows IV injections only enter the system 20 to 40 minutes faster than IM or SubQ. For urgent issues, always consult a veterinarian rather than switching administration methods yourself.

How to Clean and Maintain Syringes

Thomson explains for large doses or multiple administrations, a pistol grip syringe is more efficient. When only one dose or a small dose is given, a disposable syringe is sufficient.

He suggests these strategies for cleaning:

Disposable Syringes: Do not reuse or clean; dispose of after a single-product use.
Pistol Grip Syringes: Clean the exterior of all manure and debris. To sterilize, use hot water flushes, boiling or the microwave method — fill syringe with water, wrap in five to 10 layers of wet paper towels and microwave for 4 to 5 minutes. After they are cleaned, allow them to dry thoroughly and store in a plastic bag or a dust-free area.

Thomson adds, whenever in doubt about a practice, always consult your local veterinarian.

“Do ordinary things extraordinarily well to have a great, healthy, sustainable cow herd,” he summarizes.

Why We Need Technology and Human Expertise to Close The Mastitis Detection Gap

Tue, 10 Feb 2026 19:51:54 GMT

Mastitis detection remains constrained by parlor realities. Modern dairies are designed to maximize throughput, leaving little margin for detailed milk inspection on every cow at every milking. Even highly trained milkers can overlook subtle milk changes or early signs of disease when operating under fatigue, time pressure and competing demands.

“With how fast parlors are being pushed, workers are asked to milk more cows in shorter amounts of time. To look at and examine milk thoroughly for 8- or 12-hour shifts, it doesn’t always happen on every single cow,” says Dr. Justin Hess of Clinton Veterinary Services. “You’d be amazed at how much you can actually miss.”

Subclinical mastitis is particularly vulnerable to underdetection because it requires intentional testing that is accompanied by labor, cost and workflow implications.

Improving mastitis outcomes depends less on detection itself and more on what happens afterward. Farms today are generating more information than ever, but that information does not automatically translate into better decisions. Sound mastitis protocols need to be in place and understood by all on a dairy.

“If you try to develop a protocol, and the management team isn’t on board and you don’t have the right people in place, you’re going to struggle and probably make things more difficult,” Hess explains. “We like to keep things simple but effective.”

These protocols largely include management choices surrounding animal density, mastitis detection methods and even the choice of bedding in the stalls.

Concerning mastitis detection methods, on-farm culturing demonstrates the tension between simple and complex protocols well.

(Rose Memories Photography LLC)

“Culturing on-farm can be a struggle because of the increase in labor and having a dedicated person to do it. You also need the knowledge and desire to do it and do it correctly,” Hess says.

When farms have dedicated personnel, clear interpretation guidelines and confidence in how results will be used, culturing can reduce unnecessary antibiotic use and improve outcomes. When those conditions are absent, culturing may delay treatment without changing behavior, prompting farms to revert to broad-spectrum approaches for the sake of speed.

The challenge isn’t just the size of the farm, but the speed at which data must be converted into a treatment decision.

As the limitations of manual culturing and visual inspection become more apparent, the industry is shifting toward passive detection — systems that monitor the cow without requiring extra labor hours.

To address the complexity of dairy systems, Dr. Alon Arazi, chief veterinarian at Afimilk, hopes consolidating data generated by monitoring animals in existing protocols will help refine management and improve animal health.

“All this data is being gathered into one piece of software in which we do the analysis to detect mastitis,” Arazi says.

Sensor systems can also be used to detect mastitis based on deviations from the norm at a cow level. This baseline varies for each cow, meaning you need historical data for comparison.

“The main way to detect mastitis is based on what’s normal [for that animal]. Increased conductivity of a cow or dropped lactose to a lower level than is expected. This is mainly happening with clinical mastitis,” Arazi says. “One of the problems with subclinical mastitis is that the changes sometimes are very, very low and very hard to detect. In that case, we are looking for more and more sophisticated modeling algorithms that combine more and more things together to see things that are just starting to change.”

Mastitis Indicators Used in Automated Monitoring Systems

Automated monitoring systems identify cows suspected of mastitis by analyzing multiple milk and cow-level parameters simultaneously, rather than relying on a single signal. Key indicators include:

Milk conductivity
- Increased electrical conductivity associated with changes in ion flow during mastitis
- One of the primary and earliest milk signals used
Milk yield
- Sudden or unexpected drops in production relative to the cow’s baseline
Lactose concentration
- Decreases in lactose production when udder function is impaired
- Possible lactose leakage from milk or utilization by bacteria
Milk flow / milking dynamics
- Changes in milk flow rate that may reflect udder discomfort or inflammation
Rumination patterns
- Decreases in rumination associated with illness or discomfort
Eating behavior / dry matter intake
- Reduced intake relative to expected performance
Activity and behavior changes
- Deviations from individual cow behavioral baselines

This collected data is then compared and put into context on the individual, group and herd levels. Mastitis alerts are generated by combining multiple indicators, rather than any single threshold.

These disparate data points, along with the sheer volume of data, are where machine learning thrives.

“AI or machine learning will allow you to detect things that, even for us, are hard to see now. This for sure will improve subclinical detection,” Arazi predicts.

These systems aim to provide directional insight that shortens the time between detection and action by reducing the workload and finding changes in cow performance before they would be noticed by a worker. Catching a case 24 hours earlier could be the difference between a quick recovery and a culled cow.

“You don’t have to check every cow because the system has checked every cow two or three times in a day depending on how many milkings there are,” Arazi says. “You get the information, and you get the option to catch things earlier than people can see with their eyes.”

The Human Filter: Why Detection Requires Interpretation

Alerts without context quickly become noise. High alert frequency, poor specificity or unclear next steps can erode trust in the system. This is where veterinary intervention can help a dairy understand what they’re seeing and how best to act.

Hess stressed the questions he poses to dairies implementing updated mastitis detection protocols: “When you have that information, what are you going to do with that information? Are you going to actually change your protocols?”

Having more data is only useful for improving animal management if accompanied by a plan to act on what that data is telling you.

(Afimilk)

Technologies offering continuous observation and reduced reliance on human detection can introduce risks related to accuracy, workflow fit and trust. There is also the worry of false alerts.

“We can still improve accuracy, reduce false alerts and get more sensitivity,” Arazi says, speaking on the Afimilk system for mastitis detection.

These systems are, of course, not infallible. As with all hardware, there are uncontrollable hiccups that need to be considered when looking at the data generated.

“There are some critical parts of measuring conductivity,” Hess says. “If milk is moving or if air gets into the system, it can affect the sensitivity or the reading on it.”

At their core, these tools are designed to flag abnormal patterns, not to dictate diagnoses or management decisions. Alerts of deviations are only meaningful after interpretation by people who understand the cows, the parlor and the operation of the farm. Without the human layer, accurate detection risks becoming background noise.

“The only thing worse than no data is having wrong or misleading data,” Hess says.

The limitation is not simply technological, but decisional. This becomes most apparent when detection systems skew too far toward sensitivity at the expense of specificity. Highly sensitive tools identify earlier or more subtle changes, but they also generate more false positives. Each unnecessary alert pulls time and attention away from other priorities.

At the other end of the spectrum, overly specific systems may miss early disease signals, limiting their preventative value. Effective mastitis detection depends on deliberate trade-offs, favoring actionable accuracy over alert volume. The future of the dairy isn’t just in the data collecting sensors, but in how the person in the office uses that data to provide better care for the cow.

Does Bird Flu Have an Effect on Cow Fertility?

Fri, 06 Feb 2026 20:52:18 GMT

When highly pathogenic avian influenza (HPAI) first hit U.S. dairies, it threw the industry into unfamiliar territory. With so many unknowns, the immediate focus was on slowing the spread and caring for the cows that were affected.

Now, with more of the puzzle pieces coming together, researchers are beginning to step back and look at the bigger picture, examining how the virus affects cows not only in the days and weeks after infection, but what it may mean for their health and performance long after.

On a recent episode of “The Dairy Podcast Show”, Jennifer Spencer and Juan Pinedo, Extension dairy specialists with Texas A&M, came together to better understand what this virus is doing to reproduction — and if infected cows will be paying the price for years.

What Does HPAI Mean for Cow Fertility?

Spencer and Pinedo are just starting to study HPAI’s long-term effects, and their work is one of the first to measure how it may impact reproduction in U.S. dairy herds. Early signs point to a real effect on reproductive performance, particularly in younger animals, though the science is still evolving.

“We really want to know if it does impact reproduction,” Spencer says. “We want to let the producers know so they can understand if they might have to cull heavier to make sure that they’re managing this and replacing the cows in a timely manner — for sustainability of the herd and also to help maintain or improve their profitability.”

Like all major health events, HPAI is predicted to have an impact on cow fertility or pregnancy loss. But for Spencer and Pinedo, they are trying to figure out to what degree.

“We know that when cows get sick, they shift their energy toward fighting an infection rather than reproducing,” Spencer explains. “If these cattle that are infected with HPAI are having reduced milk production, feed intake and rumination, then there’s a high probability it’s impacting reproductive efficiency and their performance.”

Pinedo adds this pattern isn’t unique to HPAI, but still worth studying.

“Just like with any other systemic disease, having a detrimental effect in repro performance is something that we will expect,” Pinedo explains.

Dig Into Herd Data

In March 2025, Spencer’s team received rapid-response funding from USDA APHIS to study how HPAI affects reproduction in dairy herds. They designed a retrospective observational study, analyzing on-farm records from January 2021 through each herd’s HPAI outbreak and beyond.

“We’re looking at data from January 2021 until they had an HPAI outbreak,” Spencer says. “How we’re determining that is based not just on what the producer says, but by also analyzing the records and looking for that drastic drop in milk production, because that’s kind of the overall sign when they had an HPAI outbreak.”

To give the team a wide view of how HPAI is affecting herds in different settings, the project spans across three dairy regions with five to 10 dairies per region. These areas include the:

South Central
Western U.S.
Pacific Northwest

“We want to get information from different environments to have a better idea of the geographical differences, and what they deal with heat-stress-wise, or the feed availability,” Spencer says. “This will give us a 30,000' view of what is happening.”

A Hit on Heifers

While the full analysis is still in progress, the team has already taken a close look at one South Central dairy, and the early patterns are raising important questions in heifers. The study found conception rates dropped during the outbreak year but appeared to rebound the following year.

“For heifers, they actually had about a 5% decrease in their conception rates during 2024 from March until December, but that appears to go back up in 2025,” Spencer reports.

Pinedo added specific figures to put the changes into perspective.

“There was a 52% conception rate, and they dropped during the outbreak to 45%. The year after, they came back to 50%,” he notes.

These numbers show that while conception rates began to recover after the outbreak, they didn’t fully return to pre-HPAI levels. Spencer notes heifers needed more services per conception, suggesting the virus may have lingering effects on reproductive efficiency.

“For heifers, we saw an increase in services per conception, but they’ve remained higher. They went from about a 1.5 up to like 2, 2.2 number of times bred for their heifers, and it’s continuing into 2025,” she adds.

Spencer admits that wasn’t what they expected.

“We didn’t think that heifers would be impacted,” she says.

Complicating things further, some of the heifers in question were born to cows infected late in gestation.

“Some of those heifers were actually from cows that were in their third trimester of their pregnancy, so that may be a contributing factor,” Spencer adds. “There’s so many moving parts in it.”

How Are Cows Being Impacted?

For cows, the pattern is more complex. Unlike heifers, which showed a relatively clear dip and rebound in conception rates, mature cows showed more varied responses to HPAI. Some herds experienced noticeable declines during the outbreak, while others were less affected.

“We did see conception rates appeared to decrease in all of the lactations,” Spencer notes. “But for the first and third and greater lactations, they seem to be going back up, whereas the second lactation seems to be kind of having a harder time rebounding.”

Those second-lactation cows are noteworthy because many were first-lactation animals during the outbreak itself.

“It seems as if perhaps a first-lactation animal, which you might think would be more resilient to recover, maybe, is having more longer-term effects on at least reproduction, as opposed to older cattle,” Pinedo adds.

These unexpected patterns have the researchers taking a closer look at the number to try and determine why younger animals are taking a bigger reproductive hit.

How Much Should We Read Into Early HPAI Data?

While the data is eye-opening, both researchers are quick to point out that the findings are still early, and there’s a lot they don’t yet know.

“This is research that is at the very early stages, and it’s a retrospective observational study,” Pinedo emphasizes. “You really want to control confounders; it’s nothing that we could jump into conclusions [about] right now.”

He lists the kinds of changes every producer lives with year to year:

“You have bull genetics that will have changed, repro program that will have changed, feed that will have changed, heat abatement technologies, so many confounders that affect repro that have to be controlled,” he says.

Spencer sees the same complexity in the field of research.

“What if they changed a breeder? Or what if they started using precision technologies on their heifers, so their heat detection rate went up? These are things we have to take into consideration,” she says.

For now, the research is still in its early stages, but the data suggest HPAI does have reproductive effects worth paying attention to, especially in younger animals. As the team continues to analyze records and track herd performance, these early insights can help producers keep a closer eye on animals who were impacted by the virus and make more informed decisions for the long-term health and fertility of their herds.

How Technology is Changing the Game in Mastitis Prevention and Detection

Tue, 03 Feb 2026 22:14:24 GMT

Mastitis is commonly described as an infectious disease, but in real-world dairy systems, it behaves far more like a systems problem. Case rates and economic impact are shaped by the barn environment, milking routines, labor capacity and cow flow long before a pathogen is identified. Mastitis persists not because veterinarians and producers lack knowledge, but because it emerges from the interaction of multiple, interconnected management decisions.

From a practice perspective, mastitis is never truly absent on a dairy.

The Ever-Present Risk of Mastitis

“Mastitis is always something you’re managing. It’s ever-present on a dairy and something you try to manage, control, keep in check and improve upon,” says Dr. Justin Hess, veterinarian at Clinton Veterinary Services in Michigan. “It’s always at the forefront to some degree. You hope to have control measures in place and treatment protocols well developed to make it easy and fairly straightforward for a dairy, but it’s ever-present.”

(Rose Memories Photography LLC)

Even well-managed herds maintain a baseline level of mastitis that fluctuates with the season, staffing changes and parlor consistency. Therefore, the practical objective is control rather than eradication. Success is measured by manageable case rates, quick identification of infection, limited impact on bulk tank somatic cell counts and culling pressure.

“Management choices such as bedding type used in stalls, overcrowding and detection methods for mastitis can all influence the case rate,” Hess says.

This reality contrasts with the tendency to treat mastitis as an isolated event. In practice, spikes in mastitis often follow subtle changes in the environment or management system. Instead of just identifying a pathogen, the vet’s value lies in identifying the systemic failure that allowed the pathogen to thrive.

(Afimilk)

Integrating Data Into Clinical Insight

Dr. Alon Arazi, chief veterinarian at Afimilk, shares the perspective that mastitis is not just one thing, but one signal inside a much bigger system of animal health, welfare and performance. That’s where technology comes in, specifically animal health monitoring systems where signals from multiple biological inputs are combined to paint a bigger picture of cow health leading to diagnosis. Technology, such as the Afimilk system, allows for the collection of large data sets from both activity and milk monitoring hardware to help with mastitis prevention and detection. Patterns, or deviations from these patterns, can signal when a cow needs a closer look.

“Twenty years ago, a very small percentage of farms used this technology. Now they are using it much more; more farms on a larger scale,” Arazi says. “In the past it was only milk matter and milk production. Now we have much more information. Information about the behavior of the cow and also more information about the milk, such as components … which led us to improving the accuracy of [mastitis] detection.”

(Photo: Rose Memories Photography LLC)

These ideas converge on a critical point: There is not one single component of herd health management that dictates mastitis prevalence; it is the sum of the whole. New technologies improve our monitoring capabilities, but they must be applied with strong fundamentals, management and prevention practices.

Solving the Root Cause of Mastitis

“If you cull the top 5% or the top few highest cows as far as somatic cell count, you’ll remove those cows and that’s easy, right? But it doesn’t actually tell you what’s causing those cows to get to that place,” Hess says. “If you’re not changing something upstream, you’re always going to deal with an issue downstream.”

Ultimately, the shift from reactive treatment to proactive system management is what defines a modern, resilient dairy. As Dr. Hess and Dr. Arazi highlight, data and technology are powerful allies, but they function best when they empower the people on the ground to make better “upstream” decisions. By treating mastitis as a symptom of the system rather than a standalone event, dairies can move away from constant firefighting to a more predictable, profitable future.

Having spent their careers at the intersection of veterinary medicine and dairy technology, Dr. Hess and Dr. Arazi share a common passion for evolving how we look at herd health. On the first episode of The Bovine Vet Podcast , they join host Andrea Bedford to discuss why mastitis is much more than a simple infection. Together, they explore the “systems” approach to dairy management and share insights on how veterinarians and producers can use data and environment to stay ahead of the curve.

The Hardest Call in Cattle Health: When to Treat Disease

Fri, 30 Jan 2026 19:55:53 GMT

“Are we better off treating disease early or treating disease precisely?” Veterinarians of Kansas State University posed this question a recent episode of BCI Cattle Chat .

Deciding when to initiate treatment is one of the most consequential judgment calls in cattle health management. The tension between acting early and waiting for diagnostic certainty persists because there is no single correct approach. Each decision carries both biological and management consequences.

“To me, I’m looking at this and framing the question as should I be sensitive or specific in my diagnostic approach,” says Dr. Todd Gunderson, clinical assistant professor in beef production medicine at K-State.

A sensitive approach prioritizes catching disease early, accepting that some animals will receive treatment they might not truly need. A specific approach limits treatment to animals that clearly meet disease thresholds, reducing unnecessary intervention but increasing the risk of missing cases that would have benefited from earlier action. The trade-off is unavoidable.

Gunderson puts forth different clinical scenarios where either approach could be beneficial or detrimental.

“Treating scouring calves and, as a result, creating more scouring calves because I’m contaminating equipment, I’m contaminating my clothes … I’m overly aggressive at going into the calving pen,” he says.

On the other hand, waiting too long could negate any help treatment might offer.

“[If] I wait until the animal is at a pathological state where they have consolidation, they already have fibrinous pleuritis of the chest cavity or adhesion and fibrous attachments,” he says. “That animal has enough pathology that even if I kill every microbe in that animal’s system that’s causing disease, it would still not recover.”

Disease Treatment as a Dynamic Process

Rather than viewing treatment as a one-time, irreversible decision, a more effective framework treats intervention as a dynamic process. Choosing not to treat immediately does not mean choosing inaction; it means committing to close monitoring and reassessment over defined time intervals.

“I don’t get trapped into thinking that I have to make the decisions that I’m going to stick with,” says Dr. Bob Larson, professor in production medicine at K-State. “Let me make a decision today and act on it and then reassess it in 12 hours and reassess it in another 12 hours, and be flexible because I’m not good enough today to predict the next 12, 24, 72 hours and be right all the time.”

Repeated evaluations allow decisions to evolve as new information emerges, improving accuracy over time.

“Just because I acted doesn’t mean that now all my thinking is over,” Larson says. “If I act, I need to maintain vigilance, observations, reassess, be willing to change my mind.”

Make Decisions Based on the Herd

Treatment decisions should also be considered in the context of the group not in isolation. Individual animal signs can be ambiguous, but herd-level trends provide valuable context. During times of disease pressure, subtle changes might warrant treatment, while the same signs in an otherwise healthy group could justify continued observation.

“We sometimes take these decisions and try to make them in a vacuum, and you can’t do that,” says Dr. Brad White, Professor and Production Medicine Director of the Beef Cattle Institute at K-State. “Often, that individual animal is a part of a group. My expectations for that group today should impact my decision.”

This includes the recent health of the herd and the number of animals presenting as ill.

In addition, environmental and situational factors should further shape treatment thresholds. Weather conditions and recent stressors both impact disease risk and recovery potential. Incorporating these variables into treatment decisions expands diagnostic accuracy beyond the animal itself.

Neonatal Calf Distress: Managing the First 24 Hours

Fri, 23 Jan 2026 18:11:16 GMT

The first 24 hours of life represent the most vulnerable period a calf will ever experience, where oxygen deprivation, metabolic acidosis, trauma and pain can quickly overwhelm an already compromised neonate. Managing neonatal distress involves early detection, rapid assessment and decisive intervention.

Many distressed calves arrive compromised. Prolonged calving, excessive traction or repeated premature intervention increase the likelihood of hypoxia, trauma and delayed physiologic recovery. A live calf is not necessarily a stable calf. Distress is often subtle in the first minutes and can be missed if assessment relies solely on heart rate or movement.

Dr. Ryan Breuer of the University of Wisconsin School of Veterinary Medicine outlined the following early indicators of neonatal distress:

Delayed head lifting or failure to achieve sternal recumbency
Irregular, shallow or gasping respiration
Blue or pale mucous membranes
Meconium staining
Swollen head or tongue

“If calves are not trying to get up or won’t stay in sternal recumbency after 15 minutes, these calves have a very poor prognosis,” Breuer says. These calves need immediate veterinary care and are often experiencing combined hypoxia and metabolic acidosis.

“Acid is toxic to the brain and can cause scarring and neurologic death to the brain tissue,” adds Breuer, listing blindness as a neurologic sign to look out for. “These animals can’t see, or they’ll start stargazing, tipping their nose to the sky.”

Respiratory Distress: The Primary Emergency

Respiratory compromise is the most immediate life-threatening component of neonatal distress. Newborn lungs have never expanded, and even mild impairment can prevent adequate oxygen exchange.

“Open mouth and flaring nostrils are signs of respiratory distress,” explains Breuer, adding that blue tinged or cyanotic mucous membranes are also indicators that the calf is not getting enough oxygen. “If the heart rate is less than 50 beats per minute and falling, intervention is going to be needed to save them.”

Calves in respiratory distress should be placed in sternal recumbency to maximize lung expansion. Physical stimulation including vigorous rubbing, nasal septum stimulation or pressure on the nasal philtrum can trigger inspiratory reflexes and help initiate more effective breathing.

Other Distress Indicators in Calves

Meconium staining is a visible indicator that the calf experienced distress before delivery. Passage of the meconium into the uterus typically reflects prolonged time in the birth canal or delayed delivery.

“Now that the amniotic sac has ruptured, there’s mixing of the waste and what the calf is submerged in,” Breuer says. “This can cause issues down the road because it can cause difficulties in cleaning that airway.”

Calves born with meconium staining are more likely to experience respiratory compromise, difficulty clearing airways and delayed stabilization after birth.

Trauma from dystocia can contribute to pain, reduced movement, impaired breathing mechanics and delayed recovery. Swelling of the head, tongue and soft tissues can further compromise airways and oxygen delivery.

Ongoing Monitoring Through the First 24 Hours

Calves that survive an initial distress event remain at elevated risk through the first 24 hours of life. Ongoing monitoring for declining vigor, abnormal respiration or changes in responsiveness is essential as early compromise often evolves rather than resolves.

Many calves that survive neonatal distress reappear later as poor performers, respiratory cases or unexplained losses. Effective neonatal distress management is not about saving every calf but about recognizing when intervention can still alter the outcome and preventing avoidable compromise. The first 24 hours determine which calves stabilize and recover and which never fully catch up.

To learn more about the first 24 hours of neonatal calf care among other topics, check out the Dairy Cattle Welfare Council webinar series .

Managing Endotoxin Load in Cattle Vaccination Programs

Wed, 21 Jan 2026 17:14:13 GMT

Calves that look rough the day after processing are a familiar sight in both cow-calf and feedlot systems. While infection, handling stress and weather are often blamed, another contributor is increasingly part of veterinary conversations: endotoxin load associated with vaccination.

“Think about if you got the stomach flu and you’re sitting on the couch all day and you just don’t feel good. Same thing with these calves,” says Dr. Jeremi Wurtz, beef cattle technical consultant for Elanco Animal Health, when describing vaccine sweat from endotoxin stacking.

Endotoxin exposure is neither new nor is it inherently harmful. The challenge arises when cumulative exposure overwhelms an animal’s ability to respond appropriately. Understanding how endotoxin stacking occurs and how vaccine design influences that risk gives veterinarians another tool to fine-tune herd health programs.

Why does Endotoxin Load Matter?

Endotoxins, primarily lipopolysaccharides (LPS), are components of the outer membrane and cell wall of gram-negative bacteria. These can make their way into an animal’s system through natural pathogen exposure or through vaccination with killed gram-negative bacterial vaccines.

The concern is not exposure itself, but the cumulative physiologic response when multiple sources are introduced close together.

“Say we vaccinate a calf with a Mannheimia haemolytica vaccine, and then we also vaccinate that same calf with a somnus vaccine, and then we give him a Moraxella vaccine,” Wurtz says. “Sometimes there will be multiple different isolates in those vaccines, and so you’re really loading up the additive effects of those endotoxins.”

When this happens, the endotoxin load can pass a threshold causing that calf to react negatively.

What Endotoxin Load Looks Like in the Field

Clinically, endotoxin reactions can resemble early respiratory disease. Affected calves might be off feed, lethargic and slow to recover after vaccination. Timing is one of the most useful clues: Endotoxin-related responses typically appear about 24 hours post-vaccination.

“It’s usually the next day,” says Wurtz, noting the events surrounding vaccination also influence calf response. “The stress of handling those calves through the chute, maybe going from one pen to another, maybe there was a shipping event, these stressors can cause calves to have more sensitivity to endotoxins.”

The overlap in presentation with other ailments explains why endotoxin effects can go unrecognized or be attributed solely to handling or disease pressure.

Endotoxin Stacking

Endotoxin stacking most often occurs when multiple gram-negative vaccines are administered at the same time. Each product contributes its own endotoxin load and the effects are additive.

“If one vaccine has 80,000 endotoxin units, and the other has another 80,000, and another 80,000, all of a sudden you are now going to really push that calf into a susceptible state,” Wurtz says. “Any time we can minimize the stacking or loading of endotoxins is pretty important.”

In practice, spacing vaccines is not always feasible. Labor, chute time and cattle flow frequently dictate protocol designs, making vaccine selection an important variable.

Is there a Magic Number for Endotoxin Load?

There is no single endotoxin threshold that predicts clinical response.

“To say ‘oh, you have to be under 180,000 endotoxin units’ is not a real proper thing to say because it’s relative,” Wurtz says. “A 900-lb. yearling calf is going to be more tolerant to endotoxin loads than a 300-lb. calf that just got weaned.”

This variability underscores why endotoxin management is best viewed as risk reduction rather than strict compliance. Along with stress, immune and nutritional status also play a role on the endotoxin load a calf can handle.

Vaccine Handling Mistakes can Increase Endotoxins

Vaccine handling plays a critical role in endotoxin release. Freezing, thawing and aggressive agitation can damage cellular components, increasing the amount of free endotoxin delivered at injection.

“A lot of times a vaccine will say shake before using. That doesn’t mean to take it and shake it like crazy, because that can damage the antigens in there and release a lot more free endotoxin as well,” Wurtz advises. “You want to just lightly turn and rotate those vaccines so you don’t overagitate and damage those antigens.”

Proper refrigeration and storage is also important for optimizing antigen delivery by avoiding damage and minimizing free endotoxins within the vaccine.

How Low-Endotoxin Vaccines are Designed

Low-endotoxin vaccines aim to reduce exposure by limiting unnecessary bacterial components. Recombinant and subunit approaches use only the specific antigen required to stimulate immunity, avoiding much of the LPS contained in whole-cell vaccines.

The Nuplura PH and Nuplura PH+5 vaccines from Elanco are examples of these low-endotoxin vaccines. They use recombinant technology to produce and isolate leukotoxin proteins for vaccine incorporation instead of including the whole bacterial cell.

“Any time you have a full cell or cellular components in a vaccine, you’re going to have the risk of having additional endotoxin,” Wurtz says.

Practical Takeaways

Low-endotoxin vaccines are not a replacement for sound herd health planning. They are one component of risk management, alongside careful product selection, realistic stacking decisions and proper handling.

“There’s no magic number to be under for endotoxin load, but anytime we can lower it is a good opportunity,” Wurtz says.

By matching vaccine design to calf risk, veterinarians can reduce unnecessary inflammatory stress while preserving protective immunity, especially when conditions are less than ideal.

How Important is Colostrum?

Wed, 07 Jan 2026 16:50:41 GMT

A make-or-break moment for the future potential of a calf is within hours of them being born . Receiving colostrum — the first milk produced by a cow after birth that is rich in antibodies, energy, vitamins and minerals that the calf cannot obtain before birth — is essential to a calf’s future.

South Dakota State University Extension beef specialist Julie Walker says the timing of colostrum consumption in calves is critical.

“At birth they should receive at least 5% of the calf’s body weight,” Walker says. “After 24 hours, the calf’s intestine tract cannot absorb the antibodies intact.”

If the calf does not receive colostrum, Walker says you could see an increase in risk of disease, making them more susceptible to pneumonia, sours, septicemia and joint issues.

“Since they lack passive immunity without colostrum, they might be a poor doing calf,” she adds. “This can be seen later in their life. When everything goes right, calves receive colostrum from nursing on the cow.”

North Carolina State University beef Extension veterinarian Tomas Gonzalez agrees that in a normal birth, the calf should be on its feet within about an hour and nursing the cow on its own soon after.

“Most beef operations rely on this natural nursing, and when the cow has good maternal behavior and weather conditions are favorable, this approach works well,” Gonzalez says. “Still, having a colostrum management plan available as a backup is critical, as not every calf nurses adequately in the first few hours.”

Colostrum Replacement

Having a replacement plan prepared before calving helps producers manage abnormal situations quickly and effectively. Walker and Gonzales agree there are three options to replace colostrum: milking the dam to collect the colostrum, colostrum from another cow or commercially available products.

“If a newborn calf is not nursing, the first step is to milk the dam and feed her colostrum to the calf using a bottle or an esophageal feeder [after proper training by your veterinarian],” Gonzales explains. “If this is not possible, colostrum [not milk] from another healthy, properly vaccinated cow in the herd can be used.”

Walker adds that you want to only obtain colostrum from healthy cows, preferably in their third lactation.

“If you have the opportunity to pick the cow you would collect colostrum from, ideally it would be a cow in its third lactation or greater, since this would provide higher-quality colostrum than two-year-old cows,” she says. “It can be difficult to get colostrum from beef cows, so some producers may work with a local dairy producer to get colostrum and freeze it until needed.”

The third option when neither of the above is available is a colostrum replacer. Gonzales says to be sure it is a true replacer, at least 100 g IgG per dose, and not just a supplement. While colostrum replacer is not the same as colostrum from a cow, it can sometimes be the only option and is better than not receiving anything.

“When it is needed, it provides immunoglobulin that helps with passive immunity coverage,” Walker says. “Follow the label when preparing the replacer and get it into the calf as soon as possible. Our best substitute is milking another cow in the same herd, but if you can’t get that, a colostrum milk replacer or substitute is certainly the way to go, and there’s producers that will just keep that on hand just in case they need that.”

Tips For Calving Season

It is often hard to tell if a calf has nursed or not, especially on an older cow. Gonzales recommends watching every newborn long enough to see it stand and actually latch onto the teat. If it hasn’t been nursed within 1 to 2 hours of birth, then step in.

Another tip he shares is to record problem calvings and assisted colostrum feedings. This helps make cull decisions down the road and better prepare for future calving.

Have a colostrum plan before the first calf is born and keep a basic calving kit ready to be prepared before a problem occurs. He says to be sure to identify your high-risk calves, use records to spot problems and work with your veterinarian closely.

“During the calving season , remember that colostrum management is critical to giving calves a strong start and preventing avoidable losses,” Gonzales says.

Your Next Reads:
Your Calving Prep Starts Here: The Essential Checklist
What You Should Know About the 3 Stages of Calving
9 Tips to Ensure Calving Season Success

Managing Disease Risk Before It Arrives

Wed, 24 Dec 2025 14:33:17 GMT

As cattle move more frequently across regions and production systems, veterinarians are increasingly tasked with helping clients prevent the introduction of infectious disease that can persist silently and erode herd performance over time. In many cases, the greatest risk is not an outbreak, but the gradual establishment of a pathogen that is difficult or impossible to eliminate once introduced.

While biosecurity includes people, equipment and environmental considerations, animal movement remains the most important driver of infectious disease risk. This was the central topic of discussion on a recent episode of Dr. Dan Thomson’s “DocTalk.”

Why Animal Movement Drives Disease Risk

“Our biggest risk is going to come from the animal itself,” said Dr. Dustin Loy, director of the Veterinary Diagnostic Center at the University of Nebraska-Lincoln. “This is going to be something that’s going to move with the animal and be transmitted from that animal to the rest of the herd.”

Transport and commingling represent peak risk periods for disease transmission. The stressors associated with hauling, dietary change and social disruption can suppress immune function and allow latent or subclinical infections to emerge. When cattle with different exposure histories mix, pathogens can spread rapidly through immunologically naive groups.

“If we can make sure that those animals we’re sourcing have a herd health program, they’ve had those calfhood vaccines and the boosters, that they have a high level of immunity to the common diseases, that’s going to really help us prevent some amount of problems,” Loy says.

However, while vaccination programs reduce risk, they are insufficient for a number of diseases of biosecurity concern. Performing diagnostic testing before animals are purchased or moved can help identify infected animals before they enter herds.

Diseases That Define Biosecurity Risk

Several diseases are consistently central to cattle biosecurity planning due to their transition dynamics, diagnostic challenges, and long-term herd impact.

Johne’s Disease

Johne’s disease remains one of the most difficult infections to control as clinical signs don’t appear until years after the animal has been infected.

“The challenge with Johne’s is that those calves are infected when they’re a month or less in age,” Loy says. “We’re not able to test those calves until they’re at least a year and a half, and usually we want to wait until they’re two or three years old just to know if they’re infected. And so that’s a real diagnostic challenge: being able to identify those animals early.”

Due to this prolonged subclinical phase, infected animals can shed Mycobacterium avium subspecies paratuberculosis, contaminating the environment and exposing young calves. Clinical signs include progressive weight loss, decreased production and chronic diarrhea, with no effective treatment. Because diagnostic sensitivity improves with age, Loy says fecal testing at pregnancy checks provides a practical surveillance point for identifying infected adults and limiting further transmission.

Anaplasmosis

Anaplasmosis is increasingly detected outside historically endemic regions, likely due to cattle movement. Caused by Anaplasma marginale, this disease is transmitted mechanically by ticks, biting flies and contaminated instruments. Calves exposed early often develop immunity with minimal clinical disease, but infection in naive cattle can cause severe anemia, abortions and sudden death.

Importantly, vectors can only transmit the organism if infected animals are present, making the testing of incoming cattle a key biosecurity step to prevent establishing a persistent reservoir within a herd.

“If we don’t have animals with anaplasmosis coming into the area, the ticks don’t transmit anaplasmosis,” Thomson says.

Bovine Viral Diarrhea (BVD)

Despite routine vaccination, BVD remains a biosecurity concern due to persistently infected (PI) animals.

“You get cows that are infected when they’re pregnant, they infect the fetus, and then the fetus does not have an immune response to the virus, so that calf is born infected. It never clears the virus and continues to shed that throughout its life,” Loy explains.

PI animals serve as powerful sources of infection, contributing to reproductive failure, immunosuppression, respiratory disease and poor performance, even in vaccinated herds. Ear-notch testing is a practical, cost-effective method for identifying PI animals prior to commingling.

Bovine Leukosis Virus (BLV)

BLV transmission occurs through blood transfer, including needles, equipment and biting insects. While many infected cattle remain asymptomatic, a subset develop lymphoma later in life, reducing longevity and productivity. Screening animals intended for long-term retention, such as breeding stock or embryo recipients, can help prevent gradual spread within expanding herds.

Core Biosecurity Questions for Veterinarians

When advising clients on cattle purchases or movements, consider asking the following questions:

Where are the animals coming from and have they been commingled with cattle from other sources?
Are these animals being moved between groups, pastures or regions with different disease exposure histories?
Do the source animals have an established herd health program, including appropriate core vaccinations and boosters?
Can diagnostic testing be used before or shortly after movement to reduce quarantine time and uncertainty?

Effective biosecurity does not eliminate all disease risk. Instead, it allows for the identification of the most consequential threats early, before they become entrenched, expensive and difficult to control.

Rep. Cleaver Requests Information from U.S. Veterinary Schools Over Student Workload Concerns

Tue, 16 Dec 2025 14:04:41 GMT

U.S. Representative Emanuel Cleaver, D-Mo., has formally requested information from 36 accredited colleges of veterinary medicine, raising concerts about student workload and clinical training practices. Letters sent last week to schools across the country are seeking details on how institutions monitor clinical duty hours, ensure student welfare and prevent students from being overextended during required rotations.

While colleges should provide rigorous curriculums that guarantee students will receive the best education and experience possible, we must also ensure students are not being exploited.

With numerous allegations of abuse at veterinary schools, I’m demanding answers.…
— Rep. Emanuel Cleaver (@repcleaver) December 10, 2025

“I write today concerning troubling allegations of systemic abuse taking place within American veterinary medicine schools,” Cleaver wrote. “Despite a relatively small number of veterinary schools across the country, recent years have seen an explosion of students speaking out about the conditions at these programs.”

In December 2023 , fourth-year veterinary students from the School of Veterinary Medicine at the University of Pennsylvania penned a letter to their administration outlining how they were consistently working 100 hour weeks, when the Student American Veterinary Medical Association guidelines call for a cap of 80 hours per week. A similar situation was revealed at the College of Veterinary Medicine Iowa State University, with students lacking the required eight hour rest period between shifts and not having proper time for meals while on shift, despite university policies on duty hours.

“I believe strongly that our higher education institutions should provide rigorous curriculums that guarantee students will receive the best education and experience possible, ensuring they are capable and qualified when they enter into the workforce,” Cleaver said in a press release . “However, just as we have taken steps to ensure colleges and universities are not taking advantage of student athletes for institutional monetary benefit, we must ensure that students at veterinary medicine schools are not being exploited. Unfortunately, with numerous allegations of abuse, it appears we have more work to do, and I’m hopeful that these institutions will provide information to address these concerns and ensure proper protections are in place.”

The letter underscores the tension in academic medicine of balancing clinical service demands with student learning, supervision and well-being. Excessive duty hours are not only a student wellness issue, but could also affect patient safety and education quality, particularly when fatigue limits learning or decision-making.

What Veterinary Schools are Being Asked to Provide

Rep. Cleaver’s letter requests information on:

Policies governing veterinary student clinical duty hours
How schools track and enforce workload limits
Mechanisms for students to report excessive hours or unsafe conditions
Protections against retaliation for students who raise concerns
How institutions balance educational objective with clinical service demands

Cleaver requested a response from schools by year-end.

Managing Heifer Mastitis: Targeting Risk Before Freshening

Fri, 05 Dec 2025 20:44:54 GMT

Heifer mastitis is often underestimated because it occurs before an animal has even entered the milking string, but the impacts are long-lasting. Subclinical infections at calving are linked to reduced production across the entire first lactation and often throughout the cow’s lifetime. For a class of animals that has yet to return any of their rearing investment, those losses are magnified.

“It’s been identified that an animal with an increased somatic cell count in the early parts of their first lactation, those animals produce less milk throughout that first lactation and many times have decreased milk production throughout their lifetime,” says Dr. Pamela Adkins of the University of Missouri. “So we are starting out of the gate not performing as well as we could, which obviously can be quite expensive.”

Based on data presented by Adkins, what’s becoming increasingly clear from recent research is heifer mastitis is not simply early-lactation mastitis in small cows. The timing, pathogen profile and management leverage points are all distinct. Because most new infections occur before the heifer ever enters the parlor, this disease demands a prevention strategy tailored to prepartum animals.

How is mastitis in heifers different from mastitis in older cows?

Across multiple studies, higher incidences of clinical mastitis have been observed in heifers during the first few days of lactation compared to older cows.

“It’s likely that those heifers acquire those infections prior to the onset of lactation,” Adkins explains. “Therefore, a lot of our focus potentially needs to be before lactation.”

This represents a shift from how we think about lactating cows.

Culture studies of heifers reinforce this: 29% to 75% of quarters can be culture-positive before calving and over 80% may be positive at first calving and in early lactation. In older cows, early lactation infection rates tend to be around 30%.

What kinds of bacteria are causing heifer mastitis?

The types of pathogens causing infection in heifers differs from those of adult cows. Heifers show a high prevalence of infection with non-aureus staphylococci (NAS), a lower prevalence of Staphylococcus aureus, and a higher prevalence of Streptococcus spp. compared to multiparous cows.

NAS are the most common isolates in heifers, especially Staphylococcus chromogenes. These are generally considered minor mastitis pathogens as they cause only a minor inflammatory response, but Adkins advises not ignoring these bacteria because they are highly prevalent.

Interestingly, NAS infection has been linked with lower incidence of clinical mastitis, and NAS inhibit the growth of pathogen bacteria in lab settings. These results suggest NAS could have a protective effect, but Adkins acknowledges there is a lot more in vitro and in vivo work to be done on this topic.

While not the largest contributor to heifer mastitis, S. aureus infection is still common. However, without the usual parlor-based transmission pathways, the question becomes how these heifers are becoming infected.

“In older cows, we consider the parlor the major concern of where the pathogen is coming from. We know [S. aureus] can be contagious, spread from cow to cow, and we think about that happening during milking time,” Adkins says. “Obviously that’s not happening yet in heifers. Therefore, we need to think of other factors that are important in heifers.”

Some older work looked into where S. aureus was found across seven dairies. Looking beyond milk and colostrum, isolates were found on the udder skin, muzzle, rectum and vagina. Adkins proposes these body sites were an important source of S. aureus infection for heifers. These infections also vary with geography and environment. The risk factors associated with an individual farm’s management and location need to be taken into consideration.

When are heifers most at risk of getting intramammary infections?

“In order to be able to prevent it, we need to know where we should focus so that we can implement prevention strategies at the right time points to help reduce infections,” Adkins says.

Work from her own lab sampled 304 quarters from 152 Holstein heifers. In comparing primigravid and nulligravid heifers, they found pregnant heifers had a higher incidence of positive quarters than non-pregnant heifers.

“Gestation and development of the [mammary] gland associated with pregnancy seem to be risk factors for increased prevalence of intramammary infections,” Adkins says.

These infections, in both pregnant and non-pregnant heifers, are significant because that animal is still growing and developing. Any infection could interrupt that process.

How do we diagnose heifer mastitis?

Without the usual diagnostic pathway of milk culture available, defining an intramammary infection in a heifer can be a bit tricky. In most young and early gestation heifers, there isn’t enough secretion present in the mammary gland to collect a meaningful sample. Collecting swabs from the teat or teat canal might be the best option at the moment, but it might not tell the whole story either.

“A lot of bacteria hang out just in the teat canal or the teat sphincter. They don’t necessarily go up into the gland,” Adkins explains. “If we just culture the end of the teat we can find bacteria that maybe aren’t causing a problem, which complicates our definitions [of infection].”

In research, needle based methods are used to bypass the teat end and go directly to the glandular tissue. However, these methods have not been validated in the field, and Adkins heavily advises against their use on farms.

Herd level factors you should review during your visit:

Overall herd udder health: Herds with lower overall somatic cell counts tend to have less heifer mastitis. Good management practices for lactating cows influence heifer health.
Early-life management: Heifers from farms with strong colostrum SOPs show lower mastitis rates, likely due to both enhanced immunity and overall better heifer oversight. Cross-suckling remains a concern due to teat end damage.
Fly control: It has been well documented that flies can carry mastitis pathogens and move directly between teat ends.
Contact with mature cows: Some research has linked prepartum commingling with increased mastitis risk, possibly due to both pathogen exposure and stress.
Time in calving area: Longer stays in heavily contaminated maternity environments significantly increase exposure risk.

Luckily, a lot of these factors come down to management decisions.

“Heifer mastitis is a major concern in many herds. Management is always a consideration for mastitis and a major consideration in heifers as well,” Adkins says. “Mammary health is related to herd level mammary health. So taking care of mastitis at all fronts is important, and considering environmental management strategies for your heifers is vital to try to reduce infections in these animals.”

Clinical Takeaways for Vets: Managing Heifer Mastitis

Think prepartum, not parlor. Most intramammary infections in heifers are acquired before calving; prevention efforts must target the rearing and prefresh periods.

Expect a different pathogen profile. NAS (especially S. chromogenes) and Streptococci dominate. S. aureus is present but less tied to parlors and more to skin, mucosal and environmental sources.

Use herd somatic cell count as a proxy. Herds with low bulk-tank and lactating-cow SCC typically have fewer heifer infections; poor overall udder health is a red flag to investigate replacements.

Audit early-life management. Verify colostrum SOPs, prevent cross-suckling, evaluate fly burden and assess cleanliness/turnover of prefresh and calving areas. These are high-yield levers.

Beware diagnostic pitfalls. Teat-end swabs overcall “infection”; needle sampling is research-only and not appropriate on-farm. Focus on first-test-day SCC and targeted cultures from clinical quarters postcalving.

Targeted protocols over blanket therapy. Emphasize environmental and management changes first. Use selective culture-based treatment strategies in fresh heifers rather than routine prepartum intramammary therapy.