A while back, I gave a lecture to a small group of horse owners. I started the talk with a question. I asked,”Who here has herpes?” As expected, the room was silent. I explained that most everyone in there should have raised their hands. Ebstein-Barr virus, Chicken Pox, and of course sexually transmitted herpes are all examples of herpes viruses. Once you get them, you have them for life. In horses, it is the same. After a little explanation, everyone was laughing.

As of right now, there are 9 identified equine herpes viruses(EHV) in horses. The ones typically associated with disease are EHV 1, 3, and 4. EHV-1 , commonly called Rhinopneumonitis, can cause respiratory disease, neurological disease and abortions. EHV-3 is sexually transmitted and has symptoms similar to the dreaded venereal herpes in humans. EHV-4 is mostly just associated with respiratory disease, but can also cause abortions and neurological disease. The one everyone is talking about right now due to the recent outbreaks is EHV-1, so that is where we are going to focus.

With EHV-1, the most common and usually first clinical sign is a fever, usually greater than 102.0°F. Other clinical signs would be malaise, nasal discharge, or neurological signs such as hind limb incoordination or loss of tail tone. These symptoms can be the same for a multitude of different viruses also such as West Nile Virus or Eastern Equine Encephalitis Virus. So the first thing you should do with these types of clinical signs is CALL YOUR VETERINARIAN!

With the outbreaks we have been seeing the last few years, most of them are being caused by a mutated EHV-1 virus described as a neuropathogenic strain. This means it has a predisposition to cause the neurological form, the most deadly form of the disease. As it is a virus, the only treatment is usually supportive care like anti-inflammatories and IV fluids. Unfortunately, none of our current vaccines are labeled as being protective against this strain. There may be cross-protection from the vaccine strains, so definitely keep up on your Rhino boosters. So that leaves prevention as the best possible way to keep your horse healthy.

EHV-1 is transmitted mostly by direct nose to nose contact. So keeping your horses away from others at sporting events is key. Also, you can transmit the virus to you horse. Limiting your contact with other horses will prevent you from getting the virus on yourself. Do not allow your horses to use community watering troughs. At shows, disinfect your stall prior to putting your horse in it. This may be a little extra work on your part, but an inexpensive bleach solution can kill the virus. If you know there is an outbreak in the area, just do not go to the event, it is not worth risking your animal. All of these habits will reduce your risk of exposing your horse to all diseases while attending events.

So you have just arrived home after an event and find out there was a horse suspected to have EHV-1 at the event, what do you do? First, isolate your horse from others. Find a pen or round pen or turnout where there will not be contact with other horses. Clean and feed that one last. After cleaning and feeding, change your clothes and take a shower. This will limit the potential for transmitting the virus to other animals. Also, take your horse’s temperature twice daily. A simple rectal digital thermometer from the drug store works great. If after four weeks, your horse has not shown any signs, then it is unlikely that it will and you can resume your usual routine.

These are just some guidelines on what you can do. The American Association of Equine Practioners has a page dedicated to this. http://www.aaep.org/info/horse-health?publication=753. They have additional information to help keep your horse safe!