Skip to Navigation Skip to Main Content

Eddie Baggs: Christmas ponies must be tested for swamp fever

The Denton County equine industry generates an estimated $111 million annually for the local economy and includes more than 26,000 horses. With that in mind, there might be a chance that someone in the county will receive a horse or pony for Christmas. Eddie Baggs

Veterinarian Bob Hillman, executive director of the Texas Animal Health Commission, recommends that if you are planning to put a horse, donkey, mule or other domestic equine animal under the tree, be certain that it has tested negative for equine infectious anemia (EIA), also known as swamp fever or Coggin's disease.

Texas law requires that equine animals eight months or older have a negative blood (Coggin's) test for EIA, an incurable viral disease, within 12 months prior to a change in ownership. (Nursing foals, transferred with their tested dams, are exempt from the test.) The EIA test document, also known as a VS 10-11, is sufficient proof of testing.

EIA can cause equine animals to develop severe anemia. With an incubation period of two to four weeks, the virus affects the vascular (blood) system and localizes in the spleen, liver, kidney and lymph nodes. Although some infected animals exhibit no obvious clinical signs, others may become depressed or exhausted, lose weight or be unable to exercise or work. In acute cases, the animal will die.

No EIA vaccine is approved in the U.S., so animals must be protected from exposure to the virus. The disease is spread through the transfer of infected blood. This event can occur when biting insects feed on an infected equine animal and then feed on a nearby "clean" horse. Blood transfusions or the reuse of contaminated needles or medical instruments also can mechanically carry the virus from infected to clean animals.

The Texas Animal Health Commission, the state's livestock and poultry health regulatory agency, requires EIA-positive equine animals to be euthanized, donated to a research facility or maintained under quarantine for life, at least 200 yards from other horses.

Increased testing, movement controls for infected animals and greater disease awareness have helped control EIA in Texas. In 1997, 750 EIA-infected animals were detected in the state; in 2008 there were 26 initial positives; and as of December 2009, numbers dropped to about 10 EIA-infected equine animals.

EDDIE BAGGS, extension agent with the Texas AgriLife Extension office in Denton County, can be reached at 940-349-2880.