Livestock

Summer Mastitis in Cattle: Deep Welfare Analysis

In-depth welfare analysis of summer mastitis -- a severe bacterial udder infection affecting dry cows and heifers.

Key Facts

Summer mastitis is caused by a complex of bacteria including Trueperella pyogenes, transmitted by flies
It typically affects dry cows and heifers during the summer fly season
Affected animals develop a severely painful, hot, swollen quarter with foul-smelling discharge
Systemic illness including fever, toxaemia, and limb swelling is common in severe cases
The infected quarter is permanently destroyed -- animals lose productive capacity and face long-term welfare consequences
Welfare deterioration is severe and rapid -- animals with untreated summer mastitis suffer acutely
Fly control is the primary prevention -- the head fly (Hydrotaea irritans) is the principal vector
Antibiotic dry cow therapy and teat sealants protect against summer mastitis during the dry period

Welfare Significance

Summer mastitis causes some of the most intense suffering of any bacterial disease in cattle. The combination of severe local pain from the infected quarter, systemic toxaemia, and often limb swelling creates profound welfare deterioration that can develop over hours. Prevention through fly control and teat protection is far more welfare-protective than treatment of established disease.

What You Can Do

Implement fly control measures for dry cows and heifers during the summer season
Use teat sealants or antibiotic dry cow therapy at drying-off to protect against infection
Check dry cows and heifers daily during the fly season for udder abnormalities
Treat suspected summer mastitis as an emergency -- contact your vet same day