Drought Blamed for Spike in Pigeon Fever Cases

Agricultural authorities in some states are blaming persistent drought conditions for an increase in cases of pigeon fever in horses.

Pigeon fever, also known as drought distemper, is an infection caused in horses by the Corynebacterium pseudotuberculosis bacterium. The condition produces mild fever and pectoral abscesses that give an appearance similar to a pigeon's protruding breast. The abscesses can also appear along the horse's belly, on lower neck region, on limbs, or on the face. Less commonly, the condition can produce deep abscesses in a horse's lungs, kidneys, or liver. Pigeon fever is spread via insects and horse-to-horse contact, and horses can also contract the disease when bacteria from contaminated soil enters their bodies through cuts, scrapes or mucous membranes.

Mark Russell, MS, PhD, equine specialist at the University of Arkansas Cooperative Extension Service said that pigeon fever outbreaks are uncommon in Arkansas. However in January some cases were reported in drought-affected areas including Western and North Central Arkansas, he said.

Similarly, other drought-plagued states are also reporting pigeon fever outbreaks. In December 2011 the Louisiana Department of Agriculture and Forestry reported 30 cases connected to the drought. Oklahoma Assistant State Veterinarian and Equine Programming Coordinator Michael Herrin, DVM, said that veterinarians have reported treating increased numbers of pigeon fever cases in that state as well.

"Anecdotally, veterinarians are saying they've seen as many cases in 2011 as they would see in five years or more," Herrin said.

The connection between the spike in pigeon fever cases and persistent drought is straightforward, Herrin said.

"For some reason the bacterium thrives in dry conditions," he explained.

While the drought continues, Jeremy Powell, DVM, associate professor in the University of Arkansas Department of Animal Science, advises owners in affected areas to monitor their horses for signs of pigeon fever. Owners whose horses exhibit pigeon fever symptoms should contact a veterinarian for treatment options, Powell said.

In confirmed cases, infected horses should be isolated from other equids, and owners should implement good biosecurity practices.

"Any discharge from the abscess will contain the infectious bacteria," Powell said. "Dispose of contaminated bedding or other material. Any (exposed) tack or other equipment should be disinfected with a mild bleach solution and owners should always wash their hands after handling an infected horse."

About the Author

Pat Raia

Pat Raia is a veteran journalist who enjoys covering equine welfare, industry, and news. In her spare time, she enjoys riding her Tennessee Walking Horse, Sonny.

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