I was hanging out on the counter the other day when a client came in asking about Pigeon Fever. My ears perked up at the thought of chasing pigeons but it turns out this conversation had nothing to do with birds. Pigeon Fever is a syndrome cause by a very specific bacterium, Corynebacterium pseudotuberculosis, which leads to abscesses. This bacteria hasn’t been a big problem for Floridians since it prefers dry weather but this year has been different!
Let’s start with a little bit of learnin’. Pigeon Fever or Dryland Distemper or Lymphangitis is a relatively common problem in the hot, dry regions of our desert southwest. For reasons the experts don’t really understand the organism has been marching its way across the country to wetter regions. C. pseudotuberculosis is perfectly content to live in soil until drought conditions occur. At that time it seems to begin looking beyond the ground for somewhere to live and reproduce. The bacteria is readily spread by common insects like the stable fly and infects horses through any small wound.
The most common appearance of Pigeon Fever is a large swelling of the chest, so the horse looks like a pigeon, or underside of the belly. Upon further examination the swellings turn out to be large abscesses. Another, less frequent problem, is what’s known as ulcerative lymphangitis. This is a big swollen, oozing infection of the leg. Even rarer is an invasion of the internal organs such as the kidney and liver by the organism.
Once Dr. Lacher has decided that a C. pseudotuberculosis abscess is likely to be the problem she will start treatment by draining the abscess and flushing the area. The tricky part is any pus that hits the ground can contaminate the entire area so all pus must be contained and disposed of properly. Dr. Lacher said she tries to open them on concrete so bleach can be applied to the area. Opened and regularly flushed abscesses generally heal rapidly with minimal scarring. However, ulcerative lymphangitis can be very difficult to treat. These horses are placed on aggressive antibiotic therapy with both injectable antibiotics and highly concentrated therapy into veins in the affected leg. The leg is kept bandaged to help reduce swelling, absorb drainage, and keep antimicrobial ointments in place. Unfortunately chronic scarring of the leg and repeated infections are often left over effects of this form of the disease. Infection of the internal organs is treated with rest and aggressive antibiotics with a full recovery the usual outcome.
Prevention is aimed at controlling insects in the stable area and making sure any wounds are regularly addressed. The very bottom of the abdomen is a common area for us to see insect bites leading to open skin and excellent entrance sites from many diseases. SWAT fly ointment is the best way Dr. Lacher and her team has found to prevent this problem. Several groups are working on a vaccine but so far they have had no luck. The good thing in Florida is that Pigeon Fever time of year and scratches or dew poisoning time of year are not the same.
The biggest lesson I learned is, once again, if in doubt about what is going on with your horse: Call Springhill Equine! And in the meantime May your litter box be clean and your food bowl full!!