Here are some Common Questions Regarding the Equine Herpes Virus-1 (EVH1). The horse business here in North Texas is a vital part of the Fort Worth Economy and the outbreak could be devastating to that. I hope we are able to get it under control and a vaccine produced soon. Shows continue to go on but with the scary uncertainty that at anytime another out break can appear.
1. Can I get EVH1 from my horse or can my other animals get EVH1? EVH1 does not cause illness in people nor other animals.
2. Is there a test for EVH1? There are several tests to look for the virus. Nasal Swabs Tracheal or Bronchal Aveolar Washes PCR or Polymerase Chain Reaction-a blood test that looks for EVH1. This is usually done serially - more than one sample over time - looking for increase in titers, PBMC=Peripheral Blood Mononuclear Cells - blood test that looks for virus in blood cells. This test sometimes is used to identify horses with latent infection. EVH1 is found throughout the equine population. However, it is not always "pathogenic" or cause the disease.
3. If we find a carrier, can we eliminate that horse? Great question. FACT..Horses carry EVH1. There are horses that are chronic carriers of EVH1...every opportunity that the horse is stressed, like surgery, foaling, trailering, weaned, adverse weather conditions, social disruptions, ie., add new or take away a horse. Basically, anything that really stresses out a horse can cause them to start shedding the virus without really being sick themselves. With EVH1 being so widespread, it would be impossible to identify and eliminate every chronic carrier. There also would be economic ramifications. It is a risk we must realize exists and take in the horse industry.
4. My horses are due for spring shots...we have not been anywhere or plan to go anywhere for 30 days...is it OK to vaccinate as usual? Yes. The only time it would NOT be beneficial to vaccinate as usual would be if the horses were exposed to horses that had the neurological form of EVH1. That is because there is a possiblity of vaccination induced increased severity of EVH1 neurological signs. Check with your vet in your area for what to vaccinate for. Read your vaccine product label and follow the manufacturers directions for that product. Vaccine available on market today is suboptimal for EVH1. That is why frequent re-vaccination is recommended. We are vaccinating for the respiratory EVH1 in hopes of curtailing the neuro form. Incomplete vaccination for EVH1, or failure to comply with manufacturer's recommendations for their product, is one reason vaccine failure occurs. Overwhelming exposure to EVH1 is another. Exposure to a aggressive or hypervirulent strain is another reason for vaccine failure. THERE IS NO SPECIFIC VACCINE FOR THE NEURO FORM
5. If I have already used Fort Dodge Innovator Flu/Rhino, Prestige (insert vaccine name here), can I booster with that again when I need to? Yes. Read you labels for the manufacturer's recommendation. Check with your veterinarian as to what is recommended for your area. Also, be sure that you vaccinate for all the other regular routine vaccines in your area. We vaccine for EEE, WEE, tetanus, flu/rhino, rabies and WNV in our area every spring. In reference to Findlay, State Veterinarian Dr David Glauer had this to say: "All the right things had been done," said R. David Glauer, Ohio's state veterinarian. "I think they were doing everything right. They required immunizations coming in and they boosted the immunization at that barn. But no vaccines are 100 percent."
6. My blacksmith, dentist, vet, horse psychic, is coming next Friday. Is there anything special I should do? Exercise some jurisprudence. My blacksmith is only doing appointments where he knows nothing new has been in or out in the past 21 days. He is taking care to disinfect as much as possible between calls. He will not work on any new horses in a barn unless it was isolated and disease free for 3 weeks. He has horses at home and wants to be safe too. As a vet, if I go somewhere and see a neurological horse, you bet I will disinfect before I go anywhere else. I keep a spray bottle filled with the Shaklee Basic G and spray the truck and myself down!
7. What about breeding season? We live cover. This is a risk as the bringing in of new horses could bring EVH1 in. Also, these horse will have "hands-on" contact, if you will... further increasing your risk. Consider AI. If that is not possible, isolate and quarantine the new mares. 21 days is the recommended time frame. If the incoming mare has aborted...definitely wait. What if that mare aborted due to EVH1? We isolate and quarantine those mares and wait until 30 days or longer have passed to breed them again.
8. What if I think my horse was exposed? What should I do? - Isolate and quarantine. - Observe daily then, monitor temperature, nasal discharge, weakness or ataxia, abortions. - Disinfect everything. Let only one person take care of exposed horses that never cares for normal/unexposed horses. Wash hands frequently and try not to create fomites. - If mare aborts, clean up aborted fetus, placenta and disinfect the area and or stall and bedding where occured. Clean off mare and isolate and quarantine. - Even stop unnecessary traffic on and off your farm until you have gone through at least a 21 day quarantine. Once 21 days have past since last case, then you can release from quarantine.
9. Is there a treatment or cure? No, they die.
Hope this helps!
Information from Dr Sue Wilcox DVM