Though it has many aliases–including pigeon fever, dryland distemper, and false strangles–and can look gruesome on the surface, a normal Corynebacterium pseudotuberculosis infection is relatively easy to treat. Treating an infection that’s developed complications, however, is a more challenging task for veterinarians. At the 2011 American College of Veterinary Internal Medicine Forum, held June 15-18 in Denver, Colo., Lutz Goehring, DVM, MS, PhD, Dipl. ACVIM, assistant professor of equine medicine at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences, presented on common complications associated with pigeon fever.

Traditionally pigeon fever has been most common in the western United States, but has slowly spread east over the years. An affected horse generally forms external abscesses, particularly in the pectoral area (hence, the name pigeon fever), around the head, and in the udder or sheath areas.

Goehring explained that pigeon fever is typically contracted through skin abrasions or contact with contaminated soil. Insect vectors–such as horn or stable flies–are also common means of passing infection.

Goehring stated that when diagnosing C. pseudotuberculosis infections, veterinarians first try to localize the location of the abscess (if not visible on the horse’s body) using a variety of procedures including rectal exam, abdominal tap, auscultation (listening with a stethoscope) of heart and lungs, abdominal or thoracic (chest) ultrasound and/or radiology, needle aspirate with culture and cytology, blood cultures, and specific laboratory and titer testing. Additionally, it’s important to rule out other diseases that pose a similar clinical picture and blood profiles, such as Streptococcus equi, equine infectious anemia, lymphoma, or even a foreign body abscess