Dr. Jack Snyder: What You Need to Know about the Equine Herpes Virus (EHV-1)

Wellington, Florida, USA – March 16, 2021 – After a year of pandemic that drastically reduced the activity in the equestrian community, equestrians face the Equine Herpes Virus EHV-1, another major tragedy that has already cost the lives of 17 horses, with several of them having been infected while competing in Valencia. In light of the fears and doubts that most equestrians have, Jumper News sought to hear advice from the current most respected professional in the veterinary field, Dr. Jack R. Snyder DVM, PhD, Diplomate American College of Veterinary Surgeons.

Dr. Snyder’s contribution to the equestrian community is unmatched. He has a curriculum vitae that is pages and pages long, filled with the experience of an expert that has been a surgeon, professor, researcher, scientist and a lecturer at the most important schools and educational veterinary events around the world. Moreover, he has held the positions of either head surgeon, hospital director, official veterinarian, delegate and expert consultant multiple times at major events such as the Pan-American Games, World Equestrian and Olympic Games; serving also as an advisor to the FEI, and even the prestigious role of the President FEI Veterinary Commission of the 2010 World Equestrian Games in Lexington, Kentucky, USA.  

The worldwide pandemic has not stopped Dr. Snyder from looking after some of the most expensive and famous horses in the world, making miracles a reality. Perhaps, the most famous masterpiece of his ingenious work and magic hands is Vitiki, a horse that Yuri Mansur (BRA) describes as the best he has ever ridden. Vitiki suffered a life-threatening freak accident at the CHIO of Aachen back in 2018. After being operated by Dr. Snyder and having eight screws implanted on him, the 13-year-old chestnut Hanoverian (Valentino x For Expo) has miraculously returned to the top of the sport, in fact, he has been competing at the five-star classes during the 2021 Winter Equestrian Festival (WEF).

Founder of the Global Equine ServicesDr. Snyder kindly answered our request and questions, hoping to enlighten the equestrian community in regards to such an important topic.

1) As a world renowned veterinary doctor, what can you tell us about the Equine Herpes Virus EHV-1?

It is one of the five known herpes viruses, at the moment, one through five. The type one is one of the most severe ones since it can have a neurological, respiratory, abortion component and can be deadly in neonates. Although not the same kind of virus, it is very similar to COVID in the way it is transmitted, being very contagious, transmission airborne wise, it can be on clothes as well as objects that we use for horses (water feeders, buckets, tack, etc…..), going from one horse to the other without any difficulty. The virus can easily survive outside in the right environments, away from the horse, for at least one week or even up to 1 month away from the horse in really very suitable conditions.

There’s no question that biosecurity, cleaning and containment are very important. Obviously, in today’s world, many people have much more knowledge about viruses, virus contamination infections and respiratory viruses like the Coronavirus, which again, the herpes virus is very similar. It’s not the same kind of virus, but similar in the way it is transmitted. It is highly contagious and can go from horse to horse.

2) What are the symptons and what makes it so dangerous?

If a horse were to have it, often before the first direct clinical signs, there are usually spikes in temperatures 1 or 2 days after exposure and again 6-7 days post exposure, clinical signs can show up even after 2 weeks. That’s why in any situation of biosecurity, you should take temperatures at least twice a day in order to not miss temperature variations. Once clinical signs start, clinical signs can progress rapidly and  then obviously, it has potential to really cause some significant contamination or transmission to other horses.  However, the horse may be infectious at any point.

3) In simple words, how does it affect the health of the animals?

The virus attacks the blood vessels in the brain, causing an inflammatory response and injury and that leads to the neurologic signs that are seen often. It can also cause a typical respiratory part infection that has nasal discharge in a typical respiratory infection. Moreover, the equine herpes virus has an abortive effect, not only the neurological part plus infect neonates.

4) If a horse recovers from it, can it leave after-affects that hinder their sports career?

Horses can recover, recently, within the last 2-3 weeks I did arthroscopic surgery on a horse that had had the disease, just a few months ago. His case was just as bad as the ones that have been shown online. In fact, the horse came back and was pretty normal but then developed a lameness, so then we had to work on him to solve his lameness problem.

5) What are the best measures (prophylaxis, biosecurity protocols) all stakeholders in our industry must take in order to prevent it from spreading and the situation from getting out of control?

If you happen to be or have been at an event or somewhere there was potentially a horse with clinical signs or even where there are good biosecurity measures, it’s good to keep them isolated or semi-isolated horses if they are coming from affected areas, shows, areas, for 3 weeks, that’s the time frame you need to know whether things are clear or not.  During this time and even if you are at an event its good practice to take the horses temperature 2 times a day.  The testing for the disease is similar to the one of the Coronavirus, a quantitative PCR test, from blood or nasal swabs looking for viral can be done. Antibodies can be measured in the blood, best done 2 times 3 weeks apart.  Often, whenever there’s a case, risk factor, or clinical signs, the state veterinary authorities will be called, testing and isolation of that horse and possibly the location will take place.

The virus is easy to kill with common disinfectants, washing clothes in a washer with normal detergents will most likely kill the virus. A mixture of 10 parts water to 1 part bleach will also kill the virus on an inanimate object. So, any common disinfectant can work. Often, I dilute a bleach solution in my barn, it’s economically good and highly effective, not only against this virus but also against any potential infectious agent. Good barn hygiene around horses in the barn and tack continues to be extremely important, this is just another example around the world, why we should really always pay attention to biosecurity.

Over the years and all the events that not only my own horses have competed at, worldwide, but the times that I have worked with the FEI at various Olympic Games and other major events, biosecurity measures have continued to increase. In Wellington, Florida, USA, the number of villagers continues to increase, making sure that at these events we do the best we can to try to prevent these types of contaminations or infections, with large groups of horses, just like large groups of people, get together.

Unlike COVID, where six-foot distancing is good, there isn’t a known minimum safe distance,  that horses must be kept apart from each.  However, any time a horse comes back from a major event, equestrian gathering, if the horse is going home the best thing to do is to keep isolated away from the other horses.  I know that’s hard in a lot of situations, but being able to at least keep the horse apart from the other horses, is important.   Ideally in a separate structure, but at least a number of stalls away.  Also important,  people working in the barn, with the horses, do all the work with the horses at the barn that have not traveled first and then to the other isolated horses.  Also good management is either washing hands between horses or using new disposable gloves between horses.    Ideally would be good to change clothes before going to the isolated horses.  

For me, with my horses, like Babalou 41, who was traveling and showing around the world, even here in Wellington when Babalou was brought back from being at an FEI competition, I would always keep her isolated from the other horses, keeping a close watch on her while also taking her temperature, just making sure, trying to minimize any potential risk, even when there wasn’t  any known cases at the time.  I’d rather do what i can at home to avoid any major issue even if it takes more time.  

6) In a time of worldwide pandemic and the EHV-1 cases in Valencia, what must  equestrians, who travel to compete around the world, be aware of in regards not only to the health of their horses but also themselves?

Traveling worldwide  taking care of some of the most famous and expensive horses around the world, traveling is part of my routine in order to treat and operate horses. Despite the pandemic, my profession has forced me to continue operating worldwide over the past year and I have been okay by being extremely careful. It is the same with horses, when working on horses in other countries even during the pandemic I do not only watch out for myself in regards to other people, keeping good hygiene, but also when going from working on one horse to another.  Whether I am working in Wellington, California, countries in South America, Europe or any part of the world, I am always doing the same thing, making sure to observe the best possible preventive methods, keeping good hygienic habits with myself and the horses. 

The constant traveling does not only bring the threat of being contaminated with COVID-19, but also the equine herpes virus to home. Just like most people who deal with horses, I am exposed to situations that require even more attention. My wife and I have a farm in Wellington where we keep some of our own horses. Frequently, I come home from working locally on other horses or from traveling from other places around the world and must pay extra attention in regards to reducing risks, requiring strict biosecurity measures. Once I do so, I don’t go and see my horses with the same clothes, I change them, wash up, appropriately doing everything that I can. I make sure that the people who work in the barn clean all the inanimate objects with good disinfectants, which can kill not only the equine herpes virus but also the Coronavirus and other infectious agents.

7) What can you tell us about the situation in Wellington?  

Any time when there’s a situation like now that we are dealing in Florida, obviously a lot of rumors go around very quickly and very fast and that can also be very harmful to what is happening. As we saw last week, the show put out a statement to make sure the equestrian community were aware of exactly where things were. I had many calls and text messages saying that were cases everywhere and that was just not true. Rumors are not good for anybody, one way or the other. Having the facts and knowing what is going on is really important. We know that we got information from Ocala and the horses are going back and forth, that poses a significant risk and we have to watch it. At the moment, at least that I am aware, in the Wellington area, we haven’t seen anything yet, so everybody has to be careful and watch and make sure that the horses are doing ok, especially, if those horses were up north (Ocala) and moved this way or were in Europe and came to the United States.

At this point, at least for us locally in Wellington, I think we have to be watchful, very carefully, to make sure that there’s nothing spreading nor moving around, obviously being clean and having good biosecurity and hygiene with our own horses. At the moment, I don’t think we are in a stage of major crisis yet, we need to be watching our part and make sure we can continue to have good horse events.

8) What advice would you give to the equestrian community at such a difficult time?

My advice to people is just what I’ve have said before and what I do do with my horses, I have a number of horses around the world, so I really, really, try to do exactly what I said before, keeping things clean, don’t have horses being in contact with other horses that have been showing and moving around, keeping good hygiene with a focus also on the people working with the horses.

The vaccine is possibly helpful in reducing viral nasal discharge and level of virus in the horse,  but it’s not directly good against the neurological form of EHV 1, horses can still catch the neurological form of EHV 1, as we have seen in some cases that the horses who have recently got sick had been vaccinated.  There’s no question that horses should be properly vaccinated against EHV and all diseases we have vaccines for, especially where the horse lives or travels.  Moving forward, we should be very careful, watch what’s going on and hopefully get through this.

To hire the services of Dr. Snyder, please call Equine Global Services at +1 (916) 397 0050.

On behalf of Jumper News and the equestrian community, we would like to thank Dr. Snyder for sharing his expertise and precious attention to bring awareness about this subject.

Source: Dr. Jack R. Snyder

Text: Lo-Ami Souza & Dr. Jack R. Snyder, no reproduction without permission.

Photo: © Dr. Jack R. Snyder (personal archives)