Equine Herpesvirus, or Rhinopneumonitis:
Other Names for Equine Herpesvirus:
- EHV-1
- EHV-4
- Rhinopneumonitis
- Rhino
- Equine abortion virus
- Equine Herpesvirus Myeloencephalopathy (when there are neurological effects
- Equine Viral Rhinopneumonitis
- Equine Herpes Virus Myeloencephalopathy
- EHM
Causes:
EVH-1 and EVH-4 are caused by a virus that affects the respiratory system of the horse. The virus is very easily spread through the air when an infected horse coughs, or on any equipment or surface the horse may come in contact with. Most mature horses will have been exposed to the virus at some point and will have built up some natural immunity. Getting the virus again means the horse may not become as sick. Youngsters such as foals and weanlings are more at risk and the virus can take hold and spread more easily.
Symptoms:
Two to ten days after being exposed to the virus the horse’s temperature may rise to 102-107°F (38.9-41.7°C). The horse may appear lethargic, refuse to eat, have a runny nose with thick mucous, develop a cough and have swollen glands beneath the jaw bones and behind the cheek bone where the hear merges into the neck. Blood tests may show low white blood cell counts. EVH-1 can cause mares to abort foals. EVH-1 can cause cause neurological damage resulting in uneven gaits. spastic movement and paralysis. EVH may also open the door to bacterial infections. Many of the symptoms of EHV may look like equine influenza and other respiratory illnesses.
Treatment:
Prevention:
Vaccines are available that will provide short term protection for your horse. You might consider this option of you are going to a lot of shows, or must travel through an area where an outbreak is occurring. Because the vaccines only last about three to six months, they need to be re-administered frequently. To prevent broodmares from miscarrying foals, a vaccine should be given starting in the fifth month of pregnancy. Mature horses may have some partial immunity against the virus, but could benefit from the vaccine. Your veterinarian is your best adviser when it comes to a vaccination schedule.
If a horse has EVH, it should be quarantined. During an outbreak in a stable, the movement of horses should be stopped. You don’t want to bring new horses in, and you don’t want resident horses taken anywhere where they may spread the virus.
Because the virus is so easily passed from horse to horse, it is very difficult to completely eradicate the possibility of a horse getting EHV. The best that can be done is to use common sense and consult your veterinarian in the face of an outbreak.