Welfare of Animals in the Dairy Industry: Mastitis

Mastitis — udder infection — is the most common and economically costly disease in dairy cattle, causing chronic pain that affects millions of cows globally.

Key Facts

Mastitis affects approximately 25% of dairy cows in the US annually
Subclinical mastitis (no visible symptoms) affects even higher proportions — up to 50% in some herds
Treatment delays are common due to cost concerns and misidentification of subclinical cases
Severe cases cause systemic illness including fever, loss of appetite, and occasionally death
Prevention through teat sanitation, dry cow therapy, and housing improvements dramatically reduces incidence

Welfare Considerations

Mastitis welfare harm is both acute (clinical cases with visible inflammation and pain) and chronic (subclinical cases causing persistent pain without visible signs). Cows with even subclinical mastitis show altered behavior, reduced feeding, and decreased milk production — all indicators of welfare compromise. Effective prevention programs that include regular somatic cell count monitoring, teat hygiene, and appropriate dry-off treatment can reduce mastitis rates by 50-80%, representing a major achievable welfare improvement.

What You Can Do

Support dairy welfare certification standards that include mastitis prevention monitoring
Choose dairy from certified producers with documented somatic cell count requirements
Advocate for mandatory mastitis reporting and treatment protocols in dairy regulations
Reduce dairy consumption or choose dairy alternatives to reduce aggregate demand pressure on herds