Sheep Mastitis: Udder Health and Welfare in Ewes

Mastitis — inflammation of the udder — is a painful and economically significant condition in dairy sheep and suckling ewes. Effective prevention and prompt treatment are essential for animal welfare.

Key Facts

Mastitis in sheep can be acute (sudden and severe), subacute, or chronic, with varying welfare impacts.
Gangrenous mastitis caused by Staphylococcus aureus or Mannheimia haemolytica can be fatal or result in loss of the affected half of the udder.
Subclinical mastitis, with no visible symptoms, reduces milk quality and production without obvious suffering but still impairs welfare.
Major pathogens include Staphylococcus aureus, Streptococcus spp., Mannheimia haemolytica, and Pasteurella spp.
Somatic cell counts (SCC) in milk are a key indicator of udder inflammation and milk quality.
Teat dipping, clean housing, good milking hygiene, and nutrition all reduce mastitis incidence.
Affected lambs may suffer from malnutrition if their dam cannot nurse them adequately.

Welfare Considerations

Mastitis causes significant pain and discomfort in affected ewes. Acute cases involve severe inflammation, fever, and systemic illness that can be life-threatening. Even subclinical mastitis impairs milk production, affecting both the ewe's welfare and the nutritional status of dependent lambs. Pain assessment and analgesia are often neglected in sheep with mastitis, as sheep are stoic animals that may not show obvious pain signs. Good welfare practice requires proactive monitoring through SCC testing, early detection protocols, appropriate antibiotic and anti-inflammatory treatment, and humane culling decisions for chronic cases that do not respond to treatment.

What You Can Do

Implement regular somatic cell count monitoring as part of a flock health program.
Ensure milking hygiene protocols are followed, including pre- and post-milking teat dipping.
Provide adequate nutrition, especially for ewes in late pregnancy and early lactation when mastitis risk is highest.
Treat affected ewes promptly with veterinary-prescribed antibiotics and non-steroidal anti-inflammatory drugs.
Cull chronically affected ewes humanely to prevent ongoing suffering and reduce reservoir of pathogens.
Work with a flock health veterinarian to develop a mastitis prevention plan tailored to your system.