With numerous horses from different areas around the country reportedly testing positive for equine herpesvirus type- 1 (EHV-1) this year, horse owners have been encouraged by officials to practice responsible biosecurity measures in order to stop the spread of the virus, which may present as a respiratory infection or a neurologic condition.
The non-neurological respiratory form of EHV-1 is said to be similar to the flu in humans, while the signs of the neurological form, which can result in death, include nasal discharge, incoordination, hind-limb weakness, loss of tail tone, lethargy, urine dribbling, head tilt and the inability to rise.
Biosecurity, as defined by the Equine Disease Communication Center (EDCC), is any procedure or measure designed to protect the population against harmful biological or biochemical substances, and is considered crucial in maintaining a horse’s health.
Among the most common advice health officials offer to horse owners is to keep their horses up-to-date on vaccinations, monitor each horse’s eating and drinking habits, and to take note of any changes in a horse’s demeanor.
The first step to disease prevention is to keep your horses on a vaccination program that meets their needs. Work with a veterinarian to develop a program that will help protect them from high-risk equine diseases.
Oklahoma Equine Hospital founding physician Dr. Joe Carter, DVM, said what he first recommends for preventing infectious disease in central Oklahoma is proper vaccination, specifically for EHV-1.
“You can’t overemphasize the importance of a good vaccination program to prevent most of the common infectious diseases, or at least to lessen the severity if your horse were to contract one,” Carter said. “What we do specifically for EHV-1, and especially in these situations where we’ve seen outbreaks across the country, is to recommend for our clients to double-dose their horses for rhino [rhinopneumonitis, or EHV] and to give an intramuscular injection along with an intranasal vaccination at the same time. We have some specific products that we are fond of and have high confidence in.”
2. Limit Exposure
Once a horse is vaccinated, everything revolves around not letting him be exposed to viruses by avoiding contact with other horses, Carter explained. He recommended disinfecting stalls upon arrival at a horse show facility prior to moving a horse into the area.
“And that means not only disinfecting, but cleaning really well using a pressure sprayer or a brush and bucket of water [with] soap to scrub the commonalities of horse feeders and horse waterers that other horses may have used,” he said. “That is probably the best way to prevent the spread of anything like the flu, strangles or EHV-type infectious diseases.”
Other safeguard precautions include caring for all healthy horses before caring for any sick horses. Always change clothes, including foot- wear, and thoroughly wash your hands after handling a sick horse and before returning to care for any healthy horses.
Also remember to disinfect any tools or equipment — including your trailer and trailer tires — that you use while at a horse show, then again after returning home. If a horse is sick, this procedure needs to be done on a daily basis.
3. Avoid Stress
Stress can compromise a horse’s immune system and make the horse more susceptible to infection. EHV is in the same family of viruses that cause canker sores and fever blisters in humans, Carter explained.
“Stress decreases the immune system,” he said. “So, when your immune system is compromised, infectious organisms have the opportunity to take hold. That’s when canker sores may break out on your lips, tongue and mouth.”
If a horse is a carrier of a virus, even though they might not have been exposed to any new horses or taken anywhere to encounter a new strain of a virus, they may exhibit signs of having contracted a disease when they become stressed.
“Horses that have never been exposed to new horses but just have maybe been moved to another pasture or have experienced a change in the weather may become stressed, particularly high-stressed horses,” Carter added.
4. Have a Plan of Action
It is also important to establish a plan of action in the event of a disease outbreak. Keep the equipment and products that will be necessary to clean and disinfect stalls on hand, and know in advance ways to isolate one or more of the horses on your property, should they become ill.
Be sure everyone who works at the facility knows how to recognize the first signs of illness and knows what to do if they suspect a horse is ill. In addition, make sure they have access to each horse’s veterinary records, particularly their vaccination history.
If an outbreak occurs locally, be sure to get information from reliable sources like the EDCC. Be wary of social media posts and instead rely on the advice of your regular veterinarian, the state veterinarian’s office and the state department of agriculture for up-to-date reports.