Recently this spring, I received an email from Cornell Cooperative Extension with information warning horse owners about “a newly emerging disease of horses — Equine Enteric Coronavirus.” It seemed important to pass along, and so I have used information for this article that was taken from information sent out by the Veterinary Support Services group at the Animal Health Diagnostic Center at the School of Veterinary Medicine at Cornell University.
I contacted our local large animal veterinarian, Dr. Joe Nebzydoski, of the Youngsville Veterinary Clinic, Youngsville, NY, to see if he had anything to relate about the disease; fortunately, he stated that he has not yet seen any cases in our immediate area of the Catskill Mountains, upstate New York.
The School of Veterinary Medicine at Cornell University, however, has recently received several calls regarding this newly recognized disease in horses. It appears to be most prevalent during the colder months and is ‘on the radar’ in the Northeast, with 38 positive or suspect samples (out of 144 received) coming from several states including New York, Connecticut, Vermont, Missouri and Connecticut.
Horse owners are cautioned to watch for symptoms that could possibly be an indication of Equine enteric coronavirus — a fever of less than or equal to 104.0 degrees, accompanied by anorexia (not eating) and lethargy. “The virus is transmitted by the fecal oral route, and signs usually tend to resolve in 1-4 days although animals can continue shedding for several weeks.”
The virus has been recently isolated from a number of outbreaks across the country. It is an enteric, or gastrointestinal, disease of equines. The length of time it can survive in the environment is yet unknown, but it is seen during the cold weather months here in the Northeastern United States from December through May. It is most often diagnosed in adult equines, usually older than two years of age.
The most common clinical signs include anorexia, lethargy and fever of less than 104.0 as mentioned above. In addition, changes in fecal character — although diarrhea is not routinely seen; mild colicky-like signs, such as if your horse lays down and looks at his sides; neurologic abnormalities such as depression, being unable to rise after lying down, lack of coordination; and in blood tests, low white blood cell count and hypoalbunemia, or low serum total protein.
According to the report, mortality is typically rare, but secondary complications including dehydration, respiratory distress and gastrointestinal translocation (passage of viable bacteria to sites outside of the intestines) can occur. “Hyperammonemia (an excess of ammonia in the blood) and associated neurological signs may be cause for mortality.”
Clinical signs of the disease generally resolve in one to four days with supportive care, and outbreaks typically last for about three weeks.
If you suspect Equine enteric coronavirus could be present, it is suggested to submit a sample for testing. Animal Health Diagnostic Center sample requirements are fresh feces submitted in an unbreakable lead-proof container on ice packs to the Equine Enteric Corona PCR laboratory via overnight courier.

Samples must be kept chilled to prevent an overgrowth of bacteria that may cause inhibition to the PCR testing. For questions and further instruction, contact the laboratory and speak to the Veterinary Support Services, Drs. Mittel, Goodrich and Thompson at 607-253-3900.
If Equine Enteric Coronavirus is suspected on your veterinarian’s differential list, the barn should be quarantined and practice appropriate biosecurity measures to control the spread of the virus, as suggested in the AAEP guidelines  — www.aaep.org/custdocs/BiosecurityGuidelinesFinal030113.pdf .
To recap, in a barn that is suspected of harboring an equine showing signs of the virus:
1. Remember that horses can continue shedding the virus in their feces for a few weeks, reports of up to 21 days, from the onset of the clinical signs.
2. The virus is shed in the manure.
3. Encourage a suspect farm to take precautions by using footbaths, individual thermometers, and disposable gloves between horses.
4. Attempt to isolate affected animals and handle them last, using separate manure handling equipment from the rest of the barn.
5. Minimize traffic into and out of the barn.