Growing Number of Horses Euthanized Due to Contagious Disease

Certainly a trainer's nightmare, the number of EIA positive tests kept growing and now numerous horses have been euthanized.

Corey Perrine/Florida Times-Union / USA TODAY NETWORK via Imagn Images

The news just keeps getting worse in the continuing story of Heath Taylor's horses in training.

The number has now increased to 16 horses across three different states that have tested positive for Equine Infectious Anemia (EIA). These numbers have been confirmed and reported by the Equine Disease Communications Center (EDCC).

With the news coming out on Thursday, October 3, seven horses were euthanized at the Los Alamitos track in Cypress, Cali. Now, an additional six horses in Texas at the Lone Star Park have been humanely put down.

According to the latest report by the United States Department of Agriculture, the EDCC made the following report:

"On September 20th and 24th, the National Veterinary Services Laboratories (NVSL) confirmed equine infectious anemia (EIA)-positive results in 4 Quarter Horse racehorses that were part of a group recently moved from racing in New Mexico to Los Alamitos in California. Several of the EIA-positive horses were showing clinical signs of EIA upon arrival to California. Testing of in-contact horses in California and epidemiologically-linked horses in Texas and New Mexico yielded an additional 12 EIA-positive horses. All 16 EIA-positive horses (7 in CA, 1 in NM, 8 in TX) were racing under the same trainer and attending the same series of sanctioned races in New Mexico in August and September. Additional exposed horses have been identified and are in the process of being tested in multiple states. The current epidemiological investigation indicates that spread of EIA among these horses occurred by iatrogenic transmission. Updates to the current situation will be posted as more information becomes available."

Some of the take away information in this report is the means of spread identified as "iatrogenic." According to the Animal and Plant Health Inspection Service, "The primary method of spread in this population is the human-facilitated transfer of EIA-contaminated blood or blood products from infected to uninfected horses."

The USDA site goes on to say that the common methods of iatrogenic transmission include:

• Re-use of needles, syringes, or intravenous administration equipment between horses,
• Blood-contamination of multi-dose vials of injectable medication,
• Illegal importation of blood or plasma products from other countries, and
• Direct blood transfusion between horses for the purpose of increasing athletic performance (blood-doping).

EIA is untreatable and usually fatal. The disease is a blood-borne virus that causes fever, depression, low platelet count, anemia, red or purple spots on the mucous membranes, muscle weakness, and muscle atrophy.

The only two available options when a horse is confirmed positive are life-long quarantine or euthanasia. Most states will mandate euthanasia given the highly contagious factor.

Prevention of the disease include sanitary living condition and insect control, as the disease can be spread by flies. Owners and trainers should always take necessary biosecurity measures including ensuring that needles and other medical supplies and equipment that could be contaminated by blood are never shared between horses. Routine EIA testing should be performed as well.