Dairy Cow Mastitis: A Major Welfare and Production Crisis

Mastitis is the most costly disease in dairy farming and causes significant pain and suffering in millions of cows annually.

Key Facts

Mastitis affects an estimated 25-40% of dairy cows at least once per lactation in intensive systems
Clinical mastitis causes visible pain including swelling, heat, redness of the udder, and systemic illness in severe cases
Subclinical mastitis causes chronic udder inflammation without obvious signs but significantly reduces welfare
Coliform mastitis (E. coli, Klebsiella) can cause life-threatening septic shock within hours if untreated
Dry cow therapy — treating all cows at dry-off with antibiotics — is under review as part of antibiotic stewardship
Selective dry cow therapy based on individual cow risk assessment reduces antibiotic use while maintaining welfare outcomes
Milking hygiene, teat preparation, and equipment maintenance are the primary preventive factors in mastitis control
Somatic cell count is a proxy measure for mastitis prevalence and is monitored through milk recording schemes

Welfare Considerations

Mastitis represents one of the largest sources of welfare harm in dairy farming by volume. When 25-40% of cows experience mastitis in a lactation, and when subclinical cases often go undetected and untreated, the aggregate suffering is enormous. Pain is significant in clinical cases and may be chronic in subclinical ones. Treatment is often delayed or inadequate because early signs are missed. A welfare-centered approach to mastitis treats it as a welfare emergency requiring prompt diagnosis and effective pain management, not just antibiotic treatment. Prevention through hygiene, equipment maintenance, and cow comfort is more welfare-positive than reactive treatment of established disease. Monitoring somatic cell count provides a herd-level welfare indicator that should trigger investigation when elevated.

What You Can Do

Support dairy welfare certification schemes that set maximum somatic cell count thresholds as welfare indicators
Advocate for mandatory pain management alongside antibiotic treatment for clinical mastitis cases
Choose dairy products from farms with documented low mastitis rates and high welfare standards
Support antibiotic stewardship programs that reduce dry cow therapy while protecting cow welfare
Engage with dairy industry bodies about mastitis prevention as a welfare priority alongside production economics
Reduce dairy consumption to lower demand pressure that drives intensification linked to high mastitis rates
Support research into mastitis prevention technologies including teat sealants, improved hygiene systems, and genetic resistance