For more than four decades, Swedish veterinarians have had a reason to pause before reaching for an antibiotic.
That pause is part of a much larger system. Antibiotic use in Swedish livestock has been tightly regulated for more than 45 years, and overall veterinary antibiotic sales have fallen about 70% since the 1980s. At the same time, veterinary-treated clinical mastitis in dairy cattle fell from 23% in 1995 to 8% in 2023. Bulk tank somatic cell count has remained around 200,000 cells/mL in recent years.
A new publication by Karin Persson Waller and Ylva Persson traces how Sweden’s approach to mastitis treatment has evolved. The story is not simply about using fewer antibiotics. It is about becoming more selective about which cows get treated, which pathogens warrant treatment and which drugs are appropriate.
The authors do not claim that antibiotic restrictions caused the decline in mastitis. No direct causal studies have established that connection. Instead, Sweden provides a long-term example of antimicrobial stewardship embedded within mastitis prevention, diagnostics, monitoring and veterinary decision-making.
How Sweden Uses Pathogen-Based Treatment for Mastitis
In Sweden, the first question isn’t necessarily which antibiotic to use. It is whether an antibiotic is likely to help.
Swedish recommendations have emphasized bacteriologic diagnosis and prognosis for decades. Antibiotics are primarily considered for acute clinical mastitis cases with a reasonable likelihood of cure. Cases with a poor prognosis may instead call for supportive care, segregation or culling, while lactational treatment of subclinical mastitis is generally avoided.
The country’s newest guidelines make those distinctions even more explicit:
- Penicillin-sensitive Staphylococcus aureus — systemic and intramammary benzylpenicillin
- Penicillin-sensitive staphylococci and streptococci — primarily intramammary benzylpenicillin
- Trueperella pyogenes — systemic benzylpenicillin
- Gram-negative bacteria — no antibiotic treatment
- Mycoplasma bovis, yeast and penicillin-resistant staphylococci — no antibiotic treatment
Sweden’s approach isn’t simply to reduce antibiotic use. It is to match treatment to the likelihood that treatment will work.
That has made benzylpenicillin the overwhelming antibiotic of choice. In 2022, it accounted for 95% of antibiotic treatments for clinical mastitis in Sweden.
Why Benzylpenicillin Is the First Choice for Mastitis in Sweden
The Swedish treatment philosophy is closely tied to the pathogens found in Nordic dairy herds.
A 2021 review of mastitis management across Denmark, Finland, Norway and Sweden found that staphylococci and streptococci were the predominant mastitis pathogens in the region, and most remained susceptible to penicillin. Gram-negative organisms such as E. coli were less prominent than in many other countries.
That helps explain why benzylpenicillin has remained the drug of choice.
For North America, the takeaway isn’t to copy Sweden’s treatment chart. Pathogen distributions, resistance patterns, available products and regulations differ among countries and herds.
The more useful lesson is the thinking behind it: a narrower diagnosis can support a narrower treatment.
Selective Dry Cow Therapy in Sweden and North America
Dry cow therapy provides perhaps the clearest comparison between the Nordic approach and traditional mastitis management elsewhere.
Blanket dry cow therapy has historically been widely used in many countries. In the Nordic countries, selective dry cow therapy has been the recommendation for decades. Selection is based on information such as SCC, mastitis history and milk-recording data, with bacteriologic diagnosis encouraged before treatment.
By 2021, 96% of surveyed Swedish farmers reported using selective dry cow therapy, with most treating 25% or fewer cows.
North American dairy medicine is moving in the same direction.
How Diagnostics and Dairy Data Guide Mastitis Treatment
The most interesting difference may not be the antibiotic, but the information available before the treatment decision is made.
The 2021 Nordic review describes extensive health and production recording across Denmark, Finland, Norway and Sweden. Milk production, SCC and veterinary-diagnosed disease are collected through national systems covering roughly 80% to 90% of cows, and veterinary treatments are recorded as well.
That gives veterinarians a much broader picture of an individual cow and her herd.
Sweden’s newest recommendations are incorporating more of those details using bacteriology, udder health classifications and lactation number when determining whether cows are candidates for dry cow treatment.
North American veterinarians increasingly have access to many of the same data: individual-cow SCC, clinical mastitis records, culture or PCR results, treatment histories and herd-level pathogen information.
The opportunity is there to turn the data already being collected into informed treatment decisions.
Does Reducing Antibiotics Affect Mastitis and Udder Health?
This is where Sweden’s experience gets particularly interesting.
The obvious concern with antimicrobial stewardship is that treating less could mean worse udder health. The Nordic data don’t support such a simple tradeoff.
Across Denmark, Finland, Norway and Sweden, clinical mastitis incidence and bulk tank SCC generally declined from the early 1990s through 2018. In 2018, treated clinical mastitis occurred at a rate of 0.10 cases per cow-year in Sweden and 0.19 in Denmark. Sweden’s more recent data show the same general pattern, with veterinary-treated clinical mastitis at 8% in 2022-23.
Those numbers don’t prove that using fewer antibiotics caused better udder health. Mastitis control is influenced by management, housing, genetics, milking systems and pathogen exposure, among other factors. They do show that low antibiotic use and good udder health can coexist.
Preventing new intramammary infections, strengthening biosecurity, monitoring udder health and improving immune protection are opportunities to reduce the need for treatment further.
What North American Veterinarians Can Learn From Sweden
Sweden’s experience isn’t a plug-and-play model for North American dairy farms. Herd size, pathogen profiles, regulations and health-recording systems differ between the regions.
The more useful question is which pieces of the Swedish approach could work in North American herds.
That could mean more routine pathogen identification before treatment, refining selective dry cow therapy, making better use of cow-level histories or reconsidering whether every mild clinical mastitis case requires an antibiotic. The right approach will depend on the herd and its existing mastitis-control program.
The 2026 paper also points toward the next opportunities for more targeted treatment, including cow-side pathogen identification, better evidence around dosage and treatment duration, more precise recommendations for route of administration, resistance monitoring and prevention of new intramammary infections.
For North American veterinarians, the lesson isn’t simply to treat fewer cows. It is to get better at identifying which cows need treatment, which infections are likely to respond and which treatments offer the best chance of success.
After 40 years, Sweden’s experience suggests antimicrobial stewardship and good mastitis control don’t have to be competing goals. Better diagnosis, prevention and treatment decisions can work together to achieve both.
