Unsuitable Decisions and Persistent Infection: The Reality of Farmer and Veterinarian Mastitis Treatment Decisions in Denmark.

Background/Objectives: Reducing antibiotic use in the dairy sector is a critical objective. This study aimed to assess whether Danish farmers were able to achieve this objective appropriately without affecting animal health. Methods: Participants chose from three options-antibiotics (ABs), no treatment (NO), and non-steroidal anti-inflammatory drugs (NSAIDs)-and their decisions were compared against a laboratory-defined 'gold standard'. Results: The results indicated that farmers' professional judgment was unreliable; they frequently misallocated antibiotic treatments, often failing to treat cows that needed them while treating those that did not. Overall, producers administered significantly fewer antibiotics than laboratory results suggested were necessary. Although veterinarians achieved better results via in-clinic bacteriological examinations, their ability to identify specific bacterial species was insufficient. Consequently, cows remain at a significant risk of persistent infection following a clinical episode, regardless of the farmer's chosen treatment. Conclusions: The study concludes that significant progress needs to be made both on farms and in veterinary clinics to ensure that the use of antibiotics is as little as possible, but as much as necessary. Until such reliability improves, unsuitable treatment will continue to compromise animal health.