By Carolyn Walsh, veterinarian

In May 2012, four cases of Equine Infectious Anemia (EIA) were confirmed in the Cariboo/Chilcotin as reported by the Canadian Food Inspection Agency. Local veterinarians say that they are aware that it is an ongoing issue in the Chilcotin.

Equine infectious anaemia (EIA), also known as ‘swamp fever’, is a viral disease that attacks the horse's immune system. There is no cure and no vaccine for this viral infection.

“This disease is alarming because there is no cure. Samples are sent to a federally –certified and approved lab, and when a test comes up positive for EIA, the federal vets are notified,” stated Dr. Hawks from the Williams Lake Vet Clinic. “Testing for the disease is required for rodeos in the US and a lot of competitive events require it—it’s a ‘portable disease.’

“If the results are positive, and if they’re suspicious, they’ll retest the animal and will test all animals that have come into contact with the animal.

“Very few rodeos in BC require the testing—it’s more common at higher-end events like horse races, and any animal crossing the border is tested,” he continued.

“This disease is always around, and in the Chilcotin it’s endemic. Out there you have wild and domestic horses intermingling. In the case of these cases of EIA, someone may have had a suspicion about their horse and had it tested.”

He said that once there are positive results from the test, the federal veterinarians show up at your house. “They take this very seriously—the consequences are profound,” he explained. “They also follow up on horses that have come into contact with the diseased animal.”

EIA is often fatal to horses but does not affect humans. Symptoms include a reoccurring fever and anemia. However, horses can also carry the virus without displaying any clinical signs and once they have become carriers, they remain infectious for life. For this reason all infected animals are usually humanely destroyed to control the spread of disease. 

Blood-sucking insects, such as horse flies, are the most common transmitters of the virus. It can also be transmitted through the use of contaminated blood or blood products, instruments or needles. Pregnant mares may pass the disease to their foals in the womb.

Dr. Hawks said that when your horse tests positive for EIA the choices the federal veterinarians give the owner are limited. “You have to be able to prove that you can keep your horse away from flies,” he said, adding that the requirements are strenuous and impractical.  

EIA is confirmed when your veterinarian takes a blood test called the ‘Coggins’ test. If EIA is confirmed, the Canadian Food Inspection Agency can order the destruction of the horse, or permanent quarantine where possible.

The horse industry is working to protect our national herd by testing horses at race tracks, shows and events, and export/import. Be advised that Coggins testing is NOT mandatory for most rodeo events, and horse owners and competitors need to be informed regarding the risks of the disease in certain areas of the Cariboo.

If you would like your horses tested for EIA, please contact your veterinary hospital.