Agriculture officials in Arkansas, Louisiana and other states are warning veterinarians to watch for signs of a potentially fatal horse disease, pigeon fever, if a drought occurs this year. In addition, a Colorado veterinarian Brian Miller says he believes outbreaks increase when dry weather turns the ground to dust that carries disease-causing bacteria into scratches and other wounds.
Dry weather threat to horses
Vet believes outbreaks of pigeon fever increase when dry weather turns the ground to dust that carries disease-causing bacteria into scratches and other wounds.
Louisiana usually has fewer than three cases per year, but the state veterinary lab confirmed 33 during last year's drought. And Louisiana State University veterinarian Rebecca S. McConnico says the number could be as high as 300, based on what veterinarians have told her.
"Pigeon fever is not very common in Arkansas," said Mark Russell, assistant professor-equine extension for the University of Arkansas System Division of Agriculture. "It's more prevalent in drier climates, but the recent drought in parts of Arkansas may be why we're seeing it now."
What was once considered a disease of California horses, pigeon fever is now a growing problem throughout the United States, with outbreaks in Oregon, Arizona, Wyoming, Idaho and several Midwestern and Eastern states.
Known by a number of names, including pigeon breast, dryland distemper, dryland strangles and false distemper, prognosis for a complete recovery is good, although some horses experience multiple episodes.
The disease occurs in three forms: external abscesses, internal abscesses and limb infection, also known as ulcerative lymphangitis.
The most common form of the disease in the United States involves external abscesses that form deep in the muscles and can be very large, giving the horse the appearance of a pigeon breast.
Pigeon fever is not necessarily a life-threatening disease, but it is highly contagious. Once introduced into the environment, the hardy bacterium that causes it is difficult to eliminate, resulting in unpredictable future outbreaks.
Contrary to its name, the equine version of the disease isn’t caught from pigeons; instead, the transmission route is thought to be flies, especially cattle horn flies, carrying the bacteria Corynebacterium pseudotuberculosis.
While rarely contagious to humans, we can easily transfer the infection from horse to horse via our hands or equipment that has touched a draining abscess. A similar strain of pigeon fever affects goats and sheep; cattle are susceptible to both versions. All it takes is a single bacterium entering a wound, abrasion, or break in the horse’s skin or mucous membranes for the disease to take hold.
Learn more about this disease by reading Pigeon Fever