veterinarians in worcester, ma
/ by /   Equine Veterinary Services / 0 comments

Equine Contagion Part 1: Equine Herpes Virus (EHV)

With the show season kicking off there comes an increased prevalence of contagious equine diseases in the country. Here’s what you need to know to keep your horse safe, whether you’re traveling to shows, clinics, group trail rides, hunter paces, or just trucking in for lessons at another farm.


Equine veterinary servicesEquine Herpesvirus (EHV) has been in the news lately for horses becoming sick at shows in NY, KY, & CA to name a few. There are multiple EHV viruses (EHV 1, 2, 3, 4, 5) that cause several different illnesses in horses, some of which are more common than others. The two most common types are EHV-1 and EHV-4 which typically cause a respiratory disease (rhinopneumonitis) that is typically mild and self-limiting (they’ll recover with supportive care and time off). Occasionally EHV-1 & 4 can cause abortion in unvaccinated mares, and even more uncommonly cause Equine Herpesvirus Myeloencephalitis (EHM) or the neurologic form of EHV. Common symptoms of EHV include fever and nasal discharge, those symptoms could progress to incoordination, depression, hind limb weakness, and loss of tail tone in cases of EHM (which again, is very rare, but life-threatening).


Standard vaccination protocols for multi-horse barns and traveling horses include vaccination for EHV-1 and EHV-4 (the “Rhino” in Flu/Rhino). Pregnant mares are also vaccinated specifically for EHV-1 to prevent abortion. Unfortunately, EHM can still occur in vaccinated horses which is why biosecurity is so important. EHV is transmitted from horse to horse through direct nose-to-nose contact, airborne droplets, and contamination of shared surfaces & equipment, even your hands, and clothing. The severity of the disease depends on the age and immune status of the individual horse. In addition to EHV, there has also been an uptick in cases of other respiratory diseases such as Strep. equi (more commonly known as “Strangles”) and equine influenza – check back for more information regarding these two diseases!


When it comes to contagious diseases, prevention is the best medicine. Just as we have become accustomed over the last year, attention to good hygiene and distancing between horses is important. When attending events or visiting other farms, avoid sharing equipment, tack, feed, water, etc., and avoid touching other horses. If you are in contact with other horses, wash your hands often, try to keep your clothes clean, change clothes when needed, and disinfect boots often. Clean and disinfect your trailer thoroughly upon returning home. Anytime horses travel off the property or new horses arrive on the farm, horses should be quarantined for 2-3 weeks prior to introducing or re-introducing them to the rest of the horses on the farm. Quarantined horses should be housed away from healthy horses, handled after all the healthy horses have been handled (i.e., clean their stalls & paddocks last), have separate equipment, and should have their temperatures taken and logged twice daily.


If you think your horse has been exposed to a contagious disease, has symptoms of a respiratory infection, or you have questions about vaccination, travel recommendations, and biosecurity, please contact EquidDoc equine veterinary services(508-885-4205 or today to discuss!


Leave a Reply