Pigeon fever actually has nothing to do with pigeons at all. Rather, it is named for the swollen pectoral muscles that generally accompany the infection. Pigeon fever has been thought of as a “West Coast” disease and traditionally California. However, cases are now being reported as far east as Kentucky and Florida and are something to be aware of.
In 2011 the Texas Veterinary Diagnostic Laboratory identified 350 positive samples for Pigeon Fever. This compared to the less than 100 positive sample for each of the years from 2005-2010. Texas experienced a severe drought in 2011, which could be one of the reasons the state saw an increase, as Pigeon fever tends to thrive in hot dry conditions.
What is Pigeon Fever?
Pigeon fever is an infection in the tissue caused by the bacteria Corynebacterium pseudotuberculosis. The bacterium tends to settle in the chest muscles. In fewer cases the bacteria will settle in the abdominal muscles, or sheath/udder or mammary glands. In rare cases it can settle in the internal organs or limbs. The infection often causes abscesses to form. These abscesses will need to be drained.
If the abscess is external (near the surface) your veterinarian should be able to drain and clean it easily. Internal abscesses (deep within the muscle tissue) often require an ultrasound to guide a trocar or large needle safely past important structures such as arteries and nerves into the abscess cavity and allow for drainage and flushing. If the abscess is external, draining and cleaning is the recommended treatment. If internal abscesses are present then long-term antibiotics will be required.
Incubation period can be three to four weeks. A horse will have swelling in the infected area from the development of abscess and may run a fever for 1-2 days. Once a horse has contracted pigeon fever they are thought to be immune from the illness for the next 5-7 years.
How is Pigeon Fever Transmitted?
The bacteria that causes Pigeon Fever lives in the environment and can spread from horse to horse. Flies are thought to be the vector transmitting the disease. Currently this disease is not an infection diagnosed in our area. However due to the frequency of horses traveling to other areas, exposure in areas where the infection is endemic increases the likelihood that our area could become contaminated.
Preventing Pigeon Fever
In infected areas, the best protection against this infectious disease is fly control. Using industry best practice to reduce the fly population in your barn is the first and biggest step in preventing the disease. Some of these best practices include proper manure management, biological control agents, and traps.
Currently there is no vaccine.