Quarter horses who compete in unsanctioned races are a high-risk group for the spread of equine infection anemia (EIA), according to the American Association of Equine Practitioners.
The organisation recently published guidelines around the viral disease, which has no cure and no vaccine for prevention.
EIA is found nearly worldwide. Most infected horses show no signs of disease. Acutely infected animals may develop a fever, go off their feed, or die suddenly.
In the chronic form, horses may develop non-specific signs such as weight loss, weakness, anemia, and swelling of the legs, chest, and abdomen.
The disease has been known for centuries but became more common in the 1930s. Infection rates peaked in the United States in the 1960s and 1970s.
The release of the Coggins test for the disease in the 1970s marked a turnaround. It allowed affected individuals to be identified and a mandatory testing regime, including for interstate movements, drastically reduced infection rates.
The online guidelines, written by Dr Katie Flynn and Dr Angela Pelzel-McCluskey, supported by the association’s Infectious Disease Committee, provide the most current information on diagnostics, transmission, risk factors, control and biosecurity strategies for the disease.
They place special emphasis on recent changes in the epidemiology (incidence, distribution and possible control) of the disease in the US.
Pelzel-McCluskey, a national equine epidemiologist for US Department of Agriculture’s APHIS Veterinary Service, says a new high-risk group has emerged in the past five years in which the primary method of disease spread is iatrogenic transmission — most commonly through needle, syringe and IV set reuse, and possibly through blood contamination of multi-dose drug vials and use of illegal blood and serum products from other countries.
“While our cases of EIA in the US used to be found primarily in untested or under-tested populations with disease spread by biting flies, the majority of EIA cases are now being found in Quarter Horse racehorses with ties to unsanctioned racing,” she says.
“Investigation of these cases has shown that unhygienic practices by the owners and trainers of these horses is spreading the disease by iatrogenic means.”
Pelzel-McCluskey advises equine vets to be aware of the potential for EIA transmission in this population and to provide educational outreach to their clients on testing high-risk horses and implementing appropriate biosecurity practices to prevent disease spread.
Pelzel-McCluskey and Flynn, who is an equine staff veterinarian at the California Department of Food and Agriculture, urge the use of a sterile needle, syringe, and IV set for all injections or treatments in horses in order to reduce the risk of spread.
They say that dental, tattoo, surgical equipment, lip chains, and bits should be thoroughly disinfected between horses, with all debris and blood removed with soap and water before disinfection.
Only commercially licensed blood or blood products should be administered.
They say open wounds should be kept clean and covered, if possible.
A sterile needle and syringe should be used each time when puncturing a multidose medication bottle.
“Use a sterile technique when drawing up and administering medications,” they said.
They urged the diligent use of good fly control through the regular mucking out of stalls, proper disposal of manure away from horse stabling areas, and the use of fly sprays or natural predators to minimize fly presence.
The guidelines can be read here.