Mastitis — inflammation of the udder — is the most economically costly and welfare-significant disease in dairy cattle worldwide, affecting millions of cows annually and causing significant pain, reduced productivity, and premature culling.
Mastitis causes genuine suffering: acute cases involve swollen, hot, painful udders, fever, reduced appetite, and in severe cases, systemic sepsis that can be fatal. Even subclinical mastitis, which is invisible to farmers, is now understood to cause chronic pain and discomfort through persistent low-grade inflammation. The condition is strongly linked to management factors including hygiene, milking practices, housing design, and metabolic stress from high-yield breeding. Welfare-centred mastitis control focuses on prevention through improved management rather than repeated antibiotic treatment of established infections.