Summer Mastitis in Cattle: Prevention of a Painful Condition

Summer mastitis is a severe bacterial udder infection affecting dry cows and heifers during summer months. Prevention through fly control and teat sealants is highly effective and prevents this extremely painful condition.

Key Facts

Summer mastitis is caused by a mixed bacterial infection including Trueperella pyogenes, often spread by the head fly Hydrotaea irritans
It affects dry cows and heifers grazing during summer, particularly in sheltered, humid areas with high fly populations
Affected quarters develop severe, painful inflammation and produce thick, foul-smelling secretion
Without prompt treatment, affected cows often lose the infected quarter permanently
Systemic illness including fever, toxaemia, and reduced appetite accompanies the local infection
Internal teat sealants applied at dry-off provide highly effective protection throughout the dry period
Fly control using insecticide ear tags and repellent treatments significantly reduces transmission risk

Welfare Considerations

Summer mastitis is acutely and severely painful — affected cattle show obvious distress including reluctance to move, kicking when the udder is touched, and marked reduction in feed intake. The systemic toxaemia can be life-threatening without prompt treatment. Preventive measures are highly effective and relatively low-cost compared to the welfare harm and economic loss of clinical disease. The combination of internal teat sealants at dry-off and effective fly control during summer represents best practice that virtually eliminates summer mastitis from well-managed herds.

What You Can Do

Apply internal teat sealants to all dry cows at dry-off as standard practice in summer mastitis risk areas
Use fly control measures including pour-on insecticides and fly traps during peak head fly season
Avoid grazing dry cows in sheltered, humid areas during peak fly activity — move to open, windswept pastures
Inspect dry cows and heifers regularly during summer for early signs of udder swelling or heat
Treat clinically affected animals immediately with systemic antibiotics and anti-inflammatory drugs