Pigeon fever outbreak plagues area horses

Several horse owners in Southwest Washington have reported cases of a highly contagious, though generally harmless, equine disease.

Pigeon fever has been reported at a cluster of properties in the Washougal area, at least one near La Center and one in Brush Prairie, said Vancouver-area equine veterinarian Randy Lee. The disease is treatable and not uncommon, though he said the cluster of cases over the past three weeks is notable.

“It’s a little unusual for it to show up like that,” Lee said.

The disease gets its name from large abscesses that typically form in the pectoral muscles of horses, causing the chest to puff out like a pigeon breast, according to a publication of Washington State University’s College of Veterinary Medicine.

The publication noted that the bacteria that causes the disease, Corynebacterium pseudotuberculosis, typically lives in the soil of arid regions. It’s popped up in Washington over the past few years.

Washougal-area stable owner Sharon Farra said the disease affected three of the eight animals kept in her stalls, including her 5-year-old mare, Daisy. Farra said the first infected animal initially exhibited a relatively small lump on the chest, about the size of three tea bags.

“We all thought it was a bad reaction to a bug bite,” she said.

Later, as the abscess developed and a veterinarian diagnosed pigeon fever, the 14-year-old mare had the site treated and pus drained. Within a week and a half, she said, the horse had healed completely.

“If there is an unusual lump on the abdomen of your horse near the girth line, you need to pay attention to it and consider that the horse is potentially contagious until you know what the lump is,” Farra said.

Lee concurred, noting that the stall area should be disinfected. The WSU publication noted that the bacteria can be transmitted by flies, which is why most cases typically appear in the late summer and fall.

“Actually, it’s around here most of the time,” said Charlie Powell, public information officer for the WSU College of Veterinary Medicine and the Washington State Veterinary Medical Association. “What happens is, people will board a horse at a boarding facility, then the horse gets pigeon fever and immediately they look to the stall to the left or to the right.”

It’s not a bad idea to be aware and cautious, he added.

“These things are very shocking to people when they occur because most horse owners are used to having healthy horses around,” he said.