Frequently Asked Questions: Equine Herpes Virus-1
February 17, 2006

 

What is Equine Herpes Virus-1 (EHV-1)?

Equine Herpes Virus-1 (EHV-1) is a contagious viral disease of horses that can cause respiratory disease, abortion and occasionally neurologic disease.

Is there another name for Equine Herpes Virus?

Rhinopneumonitis or ‘rhino.' It is a herpes virus that is common among horses.

How is the EHV-1 disease spread?

Aerosol (airborne) and fomites (feed, clothing, boots, hands, etc.)

Can EHV-1 spread to humans?

No, but people can transport the virus on their clothes, boots, etc.

Can EHV-1 spread to other species of animals?

No.

What are the clinical signs or symptoms seen with EHV-1?

Respiratory disease, abortion and occasionally neurologic disease (lack of coordination, inability to stand, etc.)

Are these clinical signs similar to any other equine diseases we have in our horse population?

Yes. Equine Influenza Virus may cause respiratory disease. Equine Viral Arteritis may cause abortions, and West Nile Virus may cause neurologic disease.

If my horse has some of the above clinical signs, will I be able to tell which disease he/she may have contracted?

No

Is there a vaccine available to help prevent the spread of EHV-1?

Yes, but it doesn't directly protect against the neurological form of the disease cause by EHV-1.

My horse is up to date on its vaccinations, including EHV-1. Can my horse still be at risk of contracting the disease?

It's possible, but horses that have not been vaccinated are at a much higher risk.

Will EHV-1 affect all of my horses or are some of my horses at more of a risk of contracting the disease?

Young, old, weak, high exposure, immune challenged, and stressed horses are more likely to get sick.

How long will it take for my horse to show clinical signs of the disease after he/she has been exposed to the disease?

Horses can shed the EHV-1 from the onset of clinical signs until 1-2 weeks after the clinical signs are gone. A 21 day quarantine period following the disease is recommended.

How do you test for EHV-1?

A blood test is available. Test results will usually take 3-7 days to be completed.

I only have one horse. Do I have to be concerned about my horse contracting EHV-1?

Yes. While the virus is spread more readily from horse to horse via infected droplets in the air, on facility surfaces, fences, buckets and a common water source, etc., there is also the possibility of spreading the disease as a result of droplets being carried on clothes, boots, jackets, etc.

As a horse owner, what should I do to prevent the potential spread of the EHV-1?

Horse owners do not need to panic, but they should following appropriate bio-security measures such as those listed at the end of this article.

What about vaccinations?

There are vaccines available to protect horses against EHV-1. Since EHV-1 is a common virus in horses, it is recommended that all horses be vaccinated at least once a year. For horses congregating at shows and competitions, more frequent vaccinations may be recommended. Consult your local veterinarian to discuss the risk potential and vaccination recommendations for your horse.

What disinfectant(s) are best to use for cleaning my facilities?

Generic disinfectants such as bleach, chlorhexidine, quaternary ammonias and others are effective in killing the EHV-1 virus.

I have only a couple horses. Do I have top follow the preventative measures?

Yes.

I have an active and full barn of horses that frequently travel through out the state and out of state. What preventative measures should I be practicing to minimize the risk of spreading EHV-1?

See the recommendations for isolation and bio-security measures listed at the end of this article. Prior to traveling with your horses, check on the current health status of horses at your final destination.

My farrier is scheduled to come and work on my horses' feet? Should I still have him/her come or cancel the visit?

Have them come unless there is a high level of disease in surrounding barns. Practice the appropriate bio-security measures, regardless of area farm status. If the work is not needed immediately and there is a high level of disease in the area, rescheduling to a later date may be the wisest decision.

If I have new horses coming to barn, what should I do before they arrive and after they arrive?

Your horses should be up to date with their EHV-1 vaccinations. Quarantine/separate the new arrivals for 3 weeks.

We like to trailer to another barn and ride. Can we still do this?

While your barn may not be under quarantine, the potential to spread the disease is minimized if horses are not exposed to additional sources of contamination. It is important to still enjoy spending time with your horse. However, by taking the initiative to keep unnecessary travel to a minimum, the potential for spreading EHV-1 will be reduced.

How long should we not travel from barn to barn during an EHV-1 outbreak?

No definitive answer can be given as the length of time is dependent on the success of minimizing the EHV-1 outbreak.

BIO-SECURITY MEASURES FOR HORSE OWNERS

• Immediately isolate any sick horses in the barn. Isolate any new horses or horses returning from another location or show for at least 7 days. If horses were exposed to sick horses while away, take further precautions and isolate horses for at least 21 days.
• As the EHV-1 virus can be spread on clothing, all human traffic (clients taking lessons, borders, visitors, trainers, blacksmiths, veterinarians) should be vigilant about disinfecting boots before entering and leaving a different barn, wearing clothing (ex: jeans, jacket) that have not been worn in another horse barn, and washing hands before handling the horses. At the entrance of the barn, provide a tub of disinfectant and instructions for all to use. Bleach water (1 part bleach to 10 parts water) may be used and should be changed daily. Phenolic based disinfectants will be less effective if a lot of feces and other organic material collects in the tub, so clean out and replace the disinfectant solution regularly.
• Do not rotate horses from stall to stall. Don't share feed tubs or water buckets among the horses. Inserting a water hose previously submerged in a bucket of a sick horse can potentially spread a virus.
• Disinfect any areas of the barn that may have been exposed to a sick horse or a horse that is of question, including disposal of all bedding and hay/feed. The above disinfectants can be used. If the stall is needed, allow disinfectant to dry before placing a horse in the same location.
• Always work with the sick horses(s) last in your chore routine and exit the barn without completing any other tasks.
• When possible, separate horses into small groups to minimize the number of horses that may be exposed if you do have an infected horse.

Copyright © 2006
Country View Veterinary Services
1350 S. Fish Hatchery Rd.
Oregon, WI 53575
608-835-0551
Updated: March 2, 2006