Summer Mastitis in Dry Cows: Welfare Prevention and Management

Summer mastitis is a severe bacterial infection of dry cows causing significant welfare impacts and requiring urgent treatment and prevention through fly control.

Key Facts

Summer mastitis is caused by Trueperella pyogenes transmitted by head flies in summer
Dry cows and heifers are primarily affected as their teat ends are more accessible to flies
Clinical signs include swollen quarters, systemic illness, fever, and foul-smelling discharge
Untreated cases cause irreversible quarter loss and can be fatal from toxaemia
Fly control using pour-on insecticides and long-acting teat sealers significantly reduces incidence

Welfare Considerations

Cows with summer mastitis experience severe pain from acute bacterial infection of the mammary gland. Systemic toxaemia from the infection causes fever, depression, and severe illness. Gangrenous changes in affected quarters cause extreme pain and necrosis. Toxaemia can be fatal without prompt treatment. Surviving cows lose the affected quarter permanently, affecting their long-term welfare from reduced milking ability. The condition is highly preventable through fly control and teat sealing, making each case a preventable welfare failure.

What You Can Do

Apply long-acting teat sealers to all dry cows and heifers before the fly season
Use pour-on insecticides for fly control on susceptible animals during summer
Check dry cows and heifers daily during fly season for early signs of summer mastitis
Treat affected animals urgently with antibiotics and anti-inflammatory medication
Avoid pastures with heavy fly burdens near water during peak summer mastitis risk periods