Mastitis — inflammation of the udder — is the most common and costly disease in dairy cows and one of the most significant welfare problems in modern dairy production.
Mastitis represents one of the clearest examples where disease prevention serves both welfare and economic interests simultaneously, yet remains highly prevalent because prevention requires management investment and discipline that variable farm practice standards do not ensure. A cow with clinical mastitis experiences significant pain from udder inflammation — the udder becomes swollen, hot, and tender, and systemic illness causes fever, reduced appetite, and the debility of acute infection. Chronic mastitis in animals that do not respond to treatment creates prolonged suffering that welfare-centered medicine would address through earlier culling decisions rather than repeated treatment attempts. Prevention programs — teat hygiene, housing cleanliness, milking equipment maintenance — are evidence-based and effective; their widespread consistent implementation would dramatically reduce mastitis welfare burden in dairy herds.