Anger Over Anaplasmosis

Despite using the recommended antibiotic-mineral mix with a VFD to prevent anaplasmosis infections, manager Jason Lewis says the Division Ranch, Strong City, Kan., lost 13 cows last year to the disease. ( Greg Henderson )

Jason Lewis discovered the first dead cow in September of last year. It was the beginning of an odyssey that left him, the ranch owner and several other area producers questioning their management, relationships with suppliers, and even government oversight on how medicated feeds are produced and the new Veterinary Feed Directive (VFD).

Over the next few weeks the number of dead cows on the 5,200-acre Division Ranch, near Strong City, Kan., where Lewis has been manager for 23 years, had grown to 13. As with any sudden loss of cattle, the deaths were at first a mystery. Initially he thought the deaths were due to blue-green algae, but an analysis of pond water was negative. 

Risk of Cattle Contracting Anaplasmosis Grows


This interactive map shows the greatest risk areas for anaplasmosis infections. Every state, except Hawaii has reported cases of anaplasmosis in cattle. An experimental vaccine from University Products LLC has been approved for veterinarian use in 26 states and Puerto Rico. Roll over each state to see more information. (Produced by Lori Hays)

 

Lewis then called on Tom Jernigan, DVM, to investigate with a necropsy and blood samples from other cows.

The diagnosis was anaplasmosis, a disease prevalent in the Kansas Flint Hills area. Lewis and Division Ranch owner Guy Pickard were well aware the ranch was in a high-risk anaplasmosis area. But that only deepened the mystery of the cow deaths because they were feeding mineral with an antibiotic designed to prevent anaplasmosis. The mineral was purchased from a local feed company that mixed chlortetracycline (CTC) into the product under a VFD written by Jernigan.

“We knew anaplasmosis was prevalent in this area,” Lewis says. “But we thought our preventative measures were protecting us.”

Over the next few months, Lewis and Pickard searched for answers to the tragedy they say cost the ranch north of $35,000. What they found is a system they believe is flawed, and now they hope their experience will serve as a warning to other cattlemen to be more vigilant.

Anaplasmosis is a disease caused by the blood parasite Anaplasma marginale. It is transmitted from animal to animal by biting flies, ticks and contaminated needles or surgical instruments. Once infected, an animal’s immune system attacks the invader, but also destroys infected red blood cells. In an acute infection, the loss of red blood cells inhibits the animal’s ability to provide adequate oxygen to tissues, and death occurs due to suffocation at the cellular level.

Producers have long known about anaplasmosis, and the most popular means of prevention is the use of mineral mixes with CTC.

Veterinarians say feeding CTC at a rate of 0.5 mg per pound of body weight will prevent anaplasmosis infections. 

When Pickard and Lewis began to suspect a problem they contacted the Kansas Department of Agriculture. A KDA representative visited the ranch, collected samples and sent them to two different labs for testing, KDA and the South Dakota Agriculture Laboratories. 

While KDA found no evidence the mineral batch to be faulty, they reported “the amount of CTC available to the cows was deficient by 56 mg to 151 mg per head per day, or 9.5% to 24.3% of the required amount to control and prevent death loss caused by anaplasmosis.”

“That appeared to be the answer at first,” Pickard says. “But the deficiencies of CTC in the mineral were within the allowable limits. So, while we were paying for a CTC-mineral mix that we thought would prevent anaplasmosis, what we were getting was a product that could legally be 30% short of the VFD as written.”

A 30% allowable variance (meaning the CTC amount could be from 70% to 130% of the VFD) is one few producers—or even many veterinarians—know about, a crucial piece of information Pickard and Lewis want to make known to other producers.

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The Food and Drug Administration’s (FDA) Center for Veterinary Medicine is the federal agency with oversight regarding the use of antibiotics in food animals. As a member of the National Cattlemen’s Beef Association, Pickard was counseled by NCBA to contact the FDA. He was referred to the FDA’s medicated feed specialist, Dragan Momcilovic, DVM. He confirmed to Pickard the FDA allows a variance of 30% for CTC in mineral mixes, a regulation that dates back at least 50 years.

In correspondence with Pickard, Momcilovic wrote regarding the justification for the variance, “the issues boil down to stating that the assay limits take into account the inherent variability in the feed assay method and give some extra allowance for variability due to mixing/sampling.

“As I would put it,” Momcilovic wrote, “the assay limits are a result of necessity dictated by and laws of physics/chemistry.”
For cowboys like Pickard and Lewis, however, the allowable variance still seems excessive. After all, both labs that tested the mineral samples from the Division Ranch indicated their tests to be 99% accurate or better.

“It’s not that simple,” says Gary Sides, beef cattle nutritionist with Zoetis, the manufacturer of Aureomycin (CTC), the only product approved by FDA for feeding as free choice in mineral to beef cattle and one many veterinarians say is the best tool for anaplasmosis prevention. 

“There are valid reasons to have a 30% variance because you can have such variation when you sample,” Sides says. “How many samples were taken? Were there any weather events such as heat and humidity? There’s just so many variables that if we reduced the variance there would be horrible ramifications for the feed companies.”

Also, it’s important for producers to understand assay variations do not predict the effectiveness of the product, says William McBeth, DVM, director of veterinary medical information and product support for Zoetis. 

“It’s a pass/fail system,” McBeth says of testing samples. “There’s real variability across all free-choice pasture mineral programs. The product is either within the allowable variance or it’s not. The assay limits are not a random number. They were developed by analytical chemists who run hundreds of samples each week.”

There’s also the crucial factor of daily intake. A VFD for CTC does not guarantee that the medication will be consumed by the cows at the recommended rate. 

“The producer has to make sure the cows are consuming the product at the recommended rate or it can’t be effective,” Sides says.

As for the feed company that provided the CTC-mineral mix to Division Ranch and others, no one believes they intentionally shorted the product. Indeed, even one of their competitors that spoke with Drovers about this story calls them “a good competitor with a good reputation.” He says like any other business, misrepresenting a feed or mineral product is a quick way to ruin their business.

“I don’t know any company that deliberately puts in 70% of what’s required,” Zoetis’ Sides says. “It’s just not done.”
Yet, the whole episode has left Lewis and Pickard feeling bitter. They provide their cattle with excellent care and management, they have a close working relationship with their veterinarian and they played by the rules of the VFD.

“We still lost 13 cows,” Pickard says. “What I want to emphasize to other producers is to be vigilant about anaplasmosis. You may be providing CTC, but it’s not a guarantee against the disease.”  

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