Warm mild weather and the emergence of more flies over the last week can only mean one thing – we are entering the risk period for summer mastitis. I heard it described once as “August bag”, but most farmers will tell you we can see it from May right up to October, if the flies are out. It typically affects dry cows and heifers, but I have treated bulls and even young calves with the condition before.

Summer mastitis is caused by a bacteria called trupella pyogenes, which is found in many abscess-like infections on our farms. When a quarter is affected, it often won’t recover or return to normal milk production and will end up permanently dry.