Every year we hear about another outbreak of herpes virus (a.k.a. rhino virus) among a group of horses.
Most horses that become infected will fight the virus off and never look back, but this virus has the potential to cause a rare debilitating neurological condition which can sometimes lead to death. This deadly form of the virus is rare, but that doesn’t mean we shouldn’t be vigilant.
The history of equine herpes viruses goes as far back to when we first domesticated horses. Equine herpes virus (EHV), as the name implies, can only infect horses and generally, unlike humans, this virus causes the horse to catch a cold for about two weeks. This virus circulates yearly among young horses and is usually fairly innocuous. As with humans, once the horse has caught the virus, it stays with them for life. During times of stress, the virus comes back out and can cause disease or be passed to other horses — continuing the life cycle.
Vaccination of young horses will prevent the respiratory disease from becoming significant, however, it does not always prevent infection of the horse. In rare cases, this virus can mutate into a form that can enter the spinal cord and brain. This is called the neurologic form. Unfortunately, once inside the brain and spinal cord, the virus causes severe damage and some horses will die. Since the virus is spread by breathing the particles out, it has the potential to spread very easily. This is the major concern among horse owners when they hear the letters EHV.
Recent outbreaks and isolated cases have prompted some concern within the local horse community. With some reasonable precautions, the spread of this virus can be limited and your horse’s health can be best protected. Some general guidelines to prevent and limit the spread are: to vaccinate your horses yearly; limit nose to nose contact with new horses; clean all pails and buckets between horses; and good hygiene practices such as washing clothes and
cleaning hands will all go a long way to preventing the spread. Horses that travel, and those in barns with many horses coming and going, will be at greatest risk.
The signs of infection are a runny nose, fever (higher than 38.5C), uncoordinated movement with the hind legs, difficulty urinating, depression and being off their feed. If you notice any of these signs in your horse, you should contact your veterinarian.
Chris Bell is an equine veterinarian and surgical specialist who operates Elders Equine Veterinary Service, with clinics in Cartier and Winnipeg. See www.eldersequineclinic.com