EHV-1 and Horses

Image: New Jersey State Police

If you’ve been paying attention to the news lately, you’ve probably heard several mentions of EHV-1 outbreaks in horses. If you’re on social media, you’ve probably seen some panicked posts by horse owners who were at an event and learned that a horse from the same event later became sick with EHV-1 type symptoms. So what is EHV-1? Should you be concerned? And what should you do as a horse owner to keep your horse safe? 

What is EHV-1?

Equine Herpesvirus (EHV) or Rhinopneumonitis are very common viruses in horses worldwide. The two most significant strains, EHV-1 and EHV-4 cause the most serious disease, including respiratory disease, abortion, and rarely neurologic disease. 

EHV-1 is a serious condition and the one that has been traced to several recent outbreaks. There can be respiratory signs or no signs at all. With broodmares, abortion is possible. In the case of the neurological disease, there may or may not be respiratory symptoms. It is contagious, and it is a reportable disease. Reportable diseases are those that are considered to be a disease of great importance and concern for the entire horse community because they are dangerous and transmissible and can severely impact animal health. You must work closely with your veterinarian who will consult with your state veterinarian if you have a suspected or confirmed case of EHV-1. 

Because of the serious nature of the disease and because it is a reportable disease, any animals, barns and/or show grounds that have been in contact with an EHV-1 positive horse must be under quarantine to avoid spreading it further. 

Symptoms may include fever, cough, clear nasal discharge, lack of coordination, wobbly gaits, difficulty urinating and/or defecating, lying down and being unable to get back up, and abortion in broodmares. 

Wellness and Baseline Temperatures

While these viruses can be very scary, fever is usually a very early symptom. But if you aren’t taking temperatures regularly, you may miss it. Taking temperatures regularly is something that we can all do easily, quickly, and inexpensively. 

You should take your horse’s temperature at home while the horse is healthy, at multiple points in the day daily for two weeks so that you know the normal baseline temperature. Be sure to record the temperature in a log each time.

Be sure that your horse has an annual wellness exam and is up to date on all recommended core and risk-based vaccines. According to the AAEP, EHV or Rhinopneumonitis is a risk-based vaccine. It protects against the respiratory form of the virus, not the neurologic. However, it may also be helpful in the event of a neurologic outbreak as it may reduce the amount of virus that the horse sheds. The EHV vaccine may be be given as part of a combo vaccine. For example, for our horses, it appears on their vaccination record as Flu/Rhino which helps to protect against Influenza and EHV or Rhino. We currently only have two horses on our farm, but both get these vaccines even if only one of them is traveling to events, just in case the traveling horse brings something home with him. This annual wellness exam and visit also helps you to establish a good working relationship with your veterinarian. If you travel with your horse to any events, you also need to have an annual Coggins test and get health papers.  

Basic Biosecurity Tips

Two horses wearing bridles are sniffing and touching nose to nose which goes against biosecurity best practices. Don't allow this kind of touching between horses from different barns.
Do Not Allow Horses to Visit Nose to Nose

If you travel with your horse to shows, clinics or trail rides, be sure to follow proper biosecurity measures, even if it’s a local show. The problem isn’t the distance that you travel, but the commingling of horses from different barns/herds that brings risk for sharing and catching diseases such as EHV. I can’t count the many times over the past few years that I’ve encountered fellow horse owners violating these basic biosecurity guidelines at shows. And it’s our responsibility as 4-H Leaders, Pony Club Leaders, trainers, barn owners and other horse professionals to teach the youth (and their parents) to follow these simple rules. 

Basic biosecurity tips to follow:

  • Do not allow horses to visit nose to nose. 
  • Be sure that others wash their hands before touching your horse, or don’t allow it. 
  • Do not share any equipment including water buckets, feed tubs, hay bags, tack, grooming tools, stall cleaning tools, or even hoses.
  • If there is a hose on a faucet at an event, be sure that the hose doesn’t touch your horse’s water bucket and DO NOT submerge it in the water in your bucket. Even better, avoid using the hose that others may have submerged in their horses’ buckets. 
  • Wash your hands between handling different horses. 
  • If stabling at an event and you have a choice of stalls, try to choose one with the best air circulation such as near doors or under overhead fans. 
  • Also, if stabling at an event, be sure that the stall is cleaned and disinfected before putting your horse in it. Use a commercial disinfectant intended for this purpose and follow the instructions. 
  • Event organizers should check health papers, vaccine records & Coggins test results, take temperatures and inspect horses for general health upon arrival at the facility. Require owners to self monitor their horses’ temperatures twice daily and record it in a log, and to look for signs of infection throughout the event. 
  • Owners should check temperatures twice daily while at the event and for two weeks after you return home. Also, isolate the horses that travel for two weeks after you return home. 
  • Owners should immediately report any signs of illness or fever to event staff. 
  • Keep your dog at home if possible, as paws are good hiding spots for contaminants. If you must bring your dog to events, keep them on a leash and bath them thoroughly as soon as you return, paying close attention to between pads and toenails. 
  • Clean and disinfect all tack and equipment after the show. 
  • On your farm, separate horses that leave the farm for showing regularly from those who don’t travel and from broodmares. 
Filling up bucket of water from hose without allowing the hose to touch the bucket or to be submerged. This is the correct way to fill horse water buckets for biosecurity best practices.
Do Not Allow the Hose to Touch or Be Submerged in the Water Bucket

What if my horse is exposed or has symptoms?

The American Association of Equine Practitioners suggests that in addition to maintaining biosecurity measures, you should take your horse’s temperature twice per day for at least 21 days if there is any potential exposure to EHV, even if they don’t have any symptoms. You must isolate the horse from all other horses to prevent it from spreading and may be required to have your horse tested.  Contact your veterinarian if the horse develops a rectal temperature greater than 101.5 F or 38.6 C (or more than 1.5 F higher than their normal baseline temperature) or if they develop any other symptoms. Your veterinarian will be able to test for EHV-1 and provide any necessary treatment. 

How can Farm Jenny Help?

Farm Jenny wants to help by making it quick and easy for you to take and record your horse’s temperature. We’ve created a temperature log in the Farm Jenny App for you to track each horse’s temperature separately on their own health page. These features are available in our free Farm Jenny app. Learn more about the app and these temperature log features here. 

We’ve integrated the Farm Jenny app with the Kinsa QuickCare Smart Thermometer. It’s as easy as syncing the thermometer with the app on your phone, clicking on your horse’s page in the app, and a few clicks later, the temperature will automatically be recorded in the Farm Jenny app on the page for that horse. It’s quick (~5-8 seconds), easy, and we’re giving away the app so that everyone can afford it.

If you don’t have a Kinsa QuickCare Smart Thermometer, you can still use the free Farm Jenny App to record and keep a temperature log for each horse in your barn by taking and entering the temperatures manually. 

To learn more about biosecurity, visit the American Association of Equine Practitioners

To get more information about the latest outbreaks in your area of the United States, visit the Equine Disease Communication Center.

You may also subscribe to the free Equine Disease Quarterly publication by the University of Kentucky’s Department of Veterinary Science which includes Worldwide disease outbreak information. 

KINSA is a registered trademark of Kinsa, Inc., San Francisco, CA
Google Play and the Google Play logo are trademarks of Google LLC.
APPLE and the Apple logo are trademarks of Apple Inc.
The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc.

Like this article?