Pigeon Fever (also called dryland distemper) has spread across North America and should be a concern for every horse owner.
As the West enters another serious drought season, this disease becomes even more prevalent as it thrives in dry soil.
Fortunately, there are preventive measures that can be taken to decrease the chances your herd will be impacted by this painful and sometimes fatal disease.
What is Pigeon Fever?
Pigeon Fever is a serious infection found in horses. It got its name from the resemblance to a pigeon’s swollen breast. This soil-borne organism is thought to be transferred through open abrasions, lacerations or fly bites.
The bacteria can cause external abscesses anywhere on the body, but mostly in the ventral midline of the belly and the pectoral region beneath the chest muscles. Internal abscesses, found on the liver, respiratory tract, kidney and spleen are less common, but more serious. In fact, up to 40 percent mortality has been reported in these cases, even with treatment.
Signs of Pigeon Fever
Pigeon Fever causes severe inflammation and local tissue damage. Outward signs of the disease can include anorexia, fever, lethargy, weight loss, respiratory tract infection, abdominal pain, and abortion in pregnant mares. It may appear as a hard lump on the chest, udder or sheath. If untreated, the disease can enter the body internally and cause death.
Diagnosing an internal infection is more challenging. Your veterinarian may use serological testing (diagnostic identification of antibodies in the serum), abdominal ultrasound, abdominocentesis (surgical puncture of the abdomen), radiographs, and subsequent laboratory analysis. The blood test is most useful when veterinarians suspect internal infection and no external abscesses are present.
It is not uncommon for horse owners to spend thousands of dollars and weeks or months treating a horse with Pigeon Fever. As the concern has grown, so have the efforts to prevent the disease.
Boehringer Ingelheim is developing a vaccine called Corynebacterium pseudotuberculosis (Pigeon Fever) Vaccine. It is being designed for horses over one year of age that do not have an active infection. Dr. Robert Hunter will publish an advisory when the vaccine becomes available.
In the meantime, horse owners can help stop the infection or minimize the spread of Pigeon Fever.
- Wear latex gloves when working with affected horses.
- Isolate affected horses to eliminate horse-to-horse contact.
- Practice meticulous wound care.
- Prevent drainage from the infected abscesses from contaminating the soil. Pigeon Fever can live up to 8 months in contaminated soil where flies can pick it up and spread the disease.
- Use fly control against stable flies, horn flies and houseflies to reduce transmission.
Pigeon Fever is not a reportable disease with the California Department of Agriculture, so advisories will not be available if there is an outbreak in your region. The best source will be your local veterinarian who can inform you of local cases and precautions to take based on your horse’s activities and physical condition.