Summer mastitis is a severe, fly-transmitted udder infection occurring in dry cows and heifers during summer months. Affected animals suffer acute systemic illness, irreversible quarter loss, and in severe cases death if treatment is delayed.
Summer mastitis causes acute, severe suffering: intense udder pain, systemic toxaemia, high fever, and rapid deterioration to recumbency over 24 to 48 hours if untreated. Detection in non-lactating animals depends on visual udder inspection and observation of behavioural changes — kicking at the udder, reluctance to walk, and abnormal posture. Welfare-centred farms inspect all dry cows and in-calf heifers daily during the fly season, apply teat sealants at drying off, and implement fly control using pour-on insecticides on affected animals and their herd mates. Prompt treatment with systemic antibiotics and supportive care is essential to prevent death and reduce suffering duration.