Tips to Keep Horses Healthy Against EHV-1

Use these 10 tips to protect your show horse before, during and after events from the threat of equine herpes virus type-1.

For the The American Quarter Horse Journal

One way to reduce the risk of transmitting EHV-1 is to limit contact with other horses. Journal photo.

1. EHV-1, EHM & EHV-4. Understanding the different strains of the equine herpesvirus can be confusing. Here’s a basic breakdown:

  • Equine herpes virus type-1 and EHV-4 are the most likely to create clinical disease, such as respiratory distress, fever, nasal discharge, cough, anorexia and abortions. 
  • EHV-1 can lead to a devastating secondary disease known as equine herpesvirus myeloencephalopathy (EHM), which causes neurologic symptoms such as hind limb ataxia or weakness, decreased tail tone, urinary incontinence and death. The prognosis for recovery for standing horses is favorable, but poor for horses that remain recumbent (laying down) for more than two days. 
  • EHM occurs rarely with EHV-4 respiratory infections, but can also occur with no previous signs of respiratory disease.

2. Protect your herd. Vaccinating your horses is a no-brainer, but this is even more important for horses kept in a large herd or at a boarding barn. If one horse contracts a contagious disease, it can spread like wildfire throughout the rest of the barn. Try to make sure the entire herd’s immunity is as strong as possible to assure each individual horse’s health. 

3. Disinfect stalls. When you bring your horse to shows and events, it doesn’t hurt to go the extra mile and disinfect your stall. Apply a disinfectant with a stiff brush to all areas of the stall, including latches, buckets, etc. A chlorhexadine-type disinfectant works well. Allow the stall to air dry, which doesn’t take very long, before re-bedding. Make sure you do this with your quarantine stalls as well.

4. Ventilation. Assuring your barn is properly ventilated can prevent respiratory diseases. Most respiratory disease are “social diseases” that are transmitted horse to horse by contact, coughing, sharing items such as waterers, feed buckets, stalls or even the same air space. As a rule of thumb, a barn should have at least eight to 10 air exchanges per hour. 

5. Mental checklist. Keep a running checklist of these steps in your head to increase biosecurity at your next show.  

  • Strip out old bedding and clean stalls with a detergent and disinfectant.
  • Limit contact with other horses or humans by putting a drape over the front of the horse’s stall or barn breezeway.
  • Don’t allow horses to touch noses.
  • Make sure handlers use a hand sanitizer each time they handle a horse.
  • Instruct visitors not to touch or feed the horse.
  • Don’t share tack or equipment.

6. Types of vaccinations. Part of being an educated horse owner is knowing how vaccinations work. All vaccines are created to help prevent disease and contain antigens, which are derived from the disease organism. A few examples of antigens are viruses and bacteria. When administered to horses, the specific vaccine helps stimulate an immune response against that particular disease. 

7. Viral vs. bacterial. It’s important to know that viruses and bacterial infections are not the same, so they must be treated differently.Unlike bacterial infections that can be treated with antibiotics, most viruses simply must run their course. Healers can do little more than treat the symptoms and provide care to support the patient’s body while its immune system fights the virus.

8. Know the symptoms. Catching a disease in its early stages is a vital component of getting a diagnosis so you can begin treatment and isolate your horse from others. Here are a few EHV symptoms to watch for: 

  • The incubation period of EHV (time from exposure to becoming ill) is one to two days with clinical signs of fever, depression, nasal discharge and loss of appetite.
  • If the neurological form of the disease occurs, it usually does so within eight to 12 days, with the horse developing clinical signs of weakness, lethargy, urine dribbling, decreased tail tone and the inability to stand.

9. Health certificate. If you have your own barn or horse property, requiring a health certificate can minimize the prevalence of infected horses intermingling with your own healthy animals. Specify to those entering your facility that you require a health certificate that is current within the past 30 days or less. 

10. Quarantine. Isolating your horse after returning from a show or event can be helpful, especially in the case that your horse contracted an undetected disease that doesn’t show up until days after you return home. This minimizes the risk of the disease spreading to other horses in your barn. Setting up a quarantine area can be as easy as dedicating one or two stalls of your barn or a small paddock to horses returning from shows or events. 

EHV-1 News Updates: Stay abreast of news regarding equine disease outbreaks in your area at