PIGEON FEVER is a common name for an infection caused by the bacterium Corynebacterium pseudotuberculosis. The reason it is called pigeon fever is that the bacteria tends to localize and form abscesses in the pectoral region and ventral abdomen of the horse, giving the horse a “pigeon-breast” appearance. This bacterium lives and multiplies in dry soil and manure and spreads through flies, other biting insects, contact with mucous membranes, or contact with the discharge from the abscesses.
This bacterium causes disease in a variety of animals, but cross-species infection is uncommon. The most likely spread would be between horses and cattle because they carry the same strain. Precautions should be taken to minimize the risk. This infection is most common to California and the West, but transportation of horses across the country makes it possible to see cases in Florida.
Clinical signs of pigeon fever can include fever (temp >101.5 degrees F), slight lameness due to swelling of the abscesses, or, in more advanced systemic cases, lethargy, decreased appetite, and severe lameness. Affected horses can develop external or internal abscesses and, in some cases, ulcerative lymphangitis of the legs.
Your veterinarian can reach a definitive diagnosis of this infection through culture of the bacteria from the abscesses.
Treatment of pigeon fever includes allowing the abscesses to mature and then draining and flushing them with a betadine solution. It is important to collect and dispose of the infectious material appropriately. Systemic antibiotics should be used only in consultation with your veterinarian, as they may complicate cases. Pain medication such as bute or banamine can help alleviate discomfort while the horse is healing. Prevention of new cases using fly control and isolation of the horse is essential!
column by DR. KATIE HENNESSY
BIO: Dr. Katie Hennessy graduated from the University of Illinois College of Veterinary Medicine in 2008 with a degree in large animal health and equine medicine. She completed an advanced internship at The Equine Medical Center of Ocala and is currently the owner and practicing veterinarian at Polk Equine. Her expertise ranges from small and exotic creatures to large animals, specializing in equine medicine.