Planning to put a horse, donkey, mule or other domestic equine animal under the tree this year? Make certain you buy, trade for or are given an animal that has been tested negative for equine infectious anemia (EIA).

Texas law requires that equine animals eight months of age or older have a negative blood test for EIA, an incurable viral disease, within 12 months prior to a change of 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. Although some infected animals exhibit no obvious clinical signs, others may become depressed, 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 blood-to-blood contact, an event that can occur when biting flies feed on an infected equine animal, then move to a nearby "clean" horse. Blood transfusions or reusing contaminated needles or veterinary medical instruments also can mechanically carry the virus from infected to clean animals.

The Texas Animal Health Commission (TAHC), the state's livestock and poultry health regulatory agency, requires EIA-positive equine animals to be euthanized, provided to a research facility, sold only for slaughter, or maintained under quarantine for life, at least 200 yards from other horses. Increased testing, movement controls for infected equine animals, and greater disease awareness has helped control EIA in Texas. In l997, 750 EIA-infected animals were detected in the state; in 2005, as of early December, about 40 EIA infected equine animals had been detected.