In the United States, there are approximately 9 million horses but fewer than 30,000 mules. Because there are so many horses in the U.S. compared to other equine species, it’s easy to think that equine infectious anemia is a condition that only affects horses. But as the name implies, this retrovirus can afflict any equine species, and there was a stark reminder of this fact when a mule in Transylvania County, North Carolina was confirmed during necropsy to have histopathological changes consistent with equine infectious anemia. As the mule was already in bad shape with EIA symptoms, the animal was euthanized before follow-up blood testing could occur. The other equine animals on the premises have tested negative for equine infectious anemia and were quarantined, observed and retested after 60 days.
This isn’t the first North Carolina case of equine infectious anemia in a mule. In 2017, there was another case in a 14 year-old female mule in Johnston County. The hot, humid climate and presence of mules, donkeys, and horses in the state make these developments all but inevitable even as the state and equine owners have done an admirable job in isolating these cases and preventing the disease from spreading.
These types of cases also provide an opportunity for state and animal health authorities to promote best practices to prevent the infection and spread of the disease in equine populations. As part of their press release on the mule-based equine infectious anemia, the North Carolina Department of Agriculture offers these tips and reminders for preventing EIA infections:
- Use sterile, disposable needles and syringes, one per equine, for all vaccines and medications.
- Test all equid for EIA every year, and at the time they enter a new premise.
- Keep stables and other facilities sanitary. Regularly clean stalls and properly dispose of manure away from equine stabling areas.
- Implement approved insect controls, such as insecticides and good drainage of standing water, to minimize fly presence.
- Only participate in events that require evidence of negative Coggins test for every equine entering the event to prevent disease introduction and spread.
- Isolate new equine on a property until they are tested for EIA.
- Never mix infected and healthy animals. Do not breed equids infected with EIA.
- Follow state laws covering EIA.