Mastitis in a Freisian mare
A young mare had weaned her foal 2 months ago with no problem and suddenly she developed an unexplained high fever while at the trainers barn. While talking on the phone with the owner I asked them to look at the udder and sure enough she had an infection of the mammary gland (mastitis). In cattle this happens quite commonly but in a mare it is much less common and can be a very serious condition that can lead to sepsis. I quickly got to work installing a jugular catheter and starting her on a course of intravenous antibiotics and antiinflammatories. With hot compresses the affected gland softened and we were able to express the milk and pus from the teat. A sterile solution of antibiotic was also infused into the udder via the teat to treat the infection locally. A sample
Of the milk was sent to the lab for bacterial culture and it showed a pure growth of Streptococcus zooepidemicus, a normal skin bacteria that had somehow gained entrance into the gland and subsequently the blood stream. This horse was fortunate to have been treated early and she responded well to the antibiotics over 7 days. By the time I returned in a week she was back to her mischevious self and no trace of an infection could be found. It’s not common for horses to get mastitis but it’s usually soon after they’ve weaned a foal and surface bacteria of the skin gain entrance through the teat into the udder. As the udder in mares is small and tucked up high in the flank it is often not noticed. The two month delay from weaning to the onset of mastitis in this mare is unusual as most symptoms occur soon after weaning. I suspect she may have had a small infection simmering that became a bigger infection once the stress of travelling and training weakened an immune system.
