preventing equine disease spread

Remember these core biosecurity steps to help keep your horses—as well as your fellow competitors’ horses—healthy

Going to a show is all about sharing—sharing friendships, stories, and sometimes even horses. That spirit of camaraderie, however, extends to bacteria, viruses, and other nasty germs. They take advantage of that environment to do some sharing of their own, racing from horse to horse and causing disease.

The challenge you face heading into show season is how to protect your horse while not sequestering yourself and your horse at the farthest corner of the showgrounds.

Show organizers, breed and discipline associations, government groups, and veterinarians have compiled lists of biosecurity do’s and don’ts. The USDA’s Animal and Plant Health Inspection Service, for example, offers a brochure with 22 bullet points of things to keep in mind.

While that’s all well and good, let’s be honest: Can anyone remember 22 bullet points at a hectic show? After all, you have to gather your tack, be sure to enter all your classes, go over patterns/tests/courses, and get your show clothes in order, not to mention handle all the details of buffing your horse into a glistening athlete who will attract the judge’s attention.

“The more complicated you make it, the lower the compliance will be,” says Nicola Pusterla, DVM, Dipl. ACVIM.

Pusterla is a professor of medicine and epidemiology at the University of California, Davis, School of Veterinary Medicine. He focuses his research on equine infectious diseases, with an emphasis on diagnosis and prevention. However, instead of insisting on a perfect protocol, Pusterla zeroes in on what we can more practically accomplish.

“The reality is if you choose three (biosecurity steps to remember)—whatever they are—there will be a great compliance and people will remember it,” Pusterla says. “It’s the ABCs or the 1-2-3s.”

In other words, fewer rules to remember will likely produce better results than a long list that people will either ignore or forget.

Nicole Scherrer, DVM, a clinical assistant professor at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center, in Kennett Square, also understands the practical approach to biosecurity. She has shown American Saddlebreds and hunter/jumpers extensively and has managed stabling for a horse show company.

Scherrer pointed out the importance of practical biosecurity not only for horses that travel to shows but also those that don’t.

“Because you’re going to be shipping back to your barn, we’re always concerned for the horses back at home, especially the young ones and the old ones,” says Scherrer. “They are usually going to be much more susceptible to disease, and they’re the ones that can get more severe disease.”

So, we’ve put together a 1-2-3 list for how to keep your horses free from disease during the upcoming show season. Following these guidelines diligently, along with their logical corollaries, can help you protect your horse and avoid having to memorize a complicated protocol.

1. Check the show venue’s stall preparations.  

While you might choose your show schedule based on goals with each horse, try to select shows held at venues with good biosecurity practices.

“The horse venues need to be better and offer grounds and boarding and holding areas that are, first of all, clean,” says Pusterla. “You shouldn’t have to go to a show, pay for the stall, and first have to muck out the stall. That stall should be clean and disinfected.”

Horse owners can try to choose venues based upon their cleanliness. But if that isn’t an option, then part of your show kit should include disinfectant and other tools to clean stalls before you put your horses in them.

“Go to the show prepared,” says Pusterla, with these supplies. “There are many disinfectants that are not caustic and that have a very short acting time. Even just removing the biological material—straw and feces—and hosing (the stall walls and other surfaces) down will help.”

Pusterla and Sherrer note that your disinfectant protocol should extend to the equipment you use. If at all possible, use separate equipment for each horse. If that isn’t possible, disinfect the equipment whenever you can, and certainly before you head home, to minimize the chance of bringing something back to your stable.

“Reduce indirect transmission,” says Pusterla, “which is transmission through equipment, hands, tack that hasn’t been cleaned and disinfected, buckets.”

A major culprit, he says, could be that wheelbarrow at the end of the shedrow filled with manure. A horse could pick up something by sniffing at the manure while you are cleaning the stall. Moving the wheelbarrow well away from your horse’s stall is an easy fix, even though it might mean a few more steps for you.

Pusterla recommends a document by the California Department of Food & Agriculture authored by Katie Flynn, BVMS, called “Biosecurity Toolkit for Equine Events.” Horse show organizers that adhere to protocols outlined in this and similar publications can greatly reduce the risk of disease transfer and outbreaks.

Scherrer says owners can be proactive by being aware of outbreaks so they can avoid shipping to a show that might pose a greater risk of infection.

“The AAEP website announces these, and we as veterinarians get email updates,” says Scherrer. “Have a good relationship with your vet so that when you’re headed somewhere, you can call your vet and ask if there have been any problems there.”

The Equine Disease Communication Center can also alert horse industry members about current disease outbreaks and information. And, of course, editors and writers at TheHorse.com report updates on such outbreaks and provide educational material on the diseases at hand.  

2. Monitor your horse and take his temperature regularly.  

Pusterla and Scherrer say this is one of the most important steps each owner can take to reduce risk of disease transmission at a show.

“Have a thermometer handy,” says Scherrer. “It’s probably the easiest thing for owners to do. Any time your horse is off feed, has a nasal discharge, or just looks depressed, take his temperature.”

If your horse has an elevated temperature, isolate him as soon and as completely as possible, whether at the show or back home. Scherrer reminds owners to tend to an ill horse last during daily chores to minimize the chance of spreading anything to other horses and to disinfect surfaces and equipment even more diligently in these cases.

“A horse may be feeling ‘off,’ and people might assume that the horse is just tired from the show,” says Scherrer. “Then they go back home, and all of a sudden multiple horses in the barn are ill. It’s important to recognize problems before you head back home.”

If your horse gets sick at the show, be considerate of your fellow competitors. Try to minimize his exposure to others, and avoid walking around the grounds with potentially contaminated clothing or equipment. That might mean missing a major class.  

Pusterla advises monitoring your horse at home even before you leave for the show and being familiar with the risks posed once you’re there.

“We had an outbreak recently of EHV-4 (equine herpesvirus-4),” says Pusterla. “Because it was a very important show, people took the risk to go to that show, taking horses to a facility that had an outbreak. In a perfect world, you don’t go to that show. But some trainers and owners just stuck their heads in the sand and went.”

Unfortunately, in some cases, horses can become infected without showing clinical signs, which can spread disease even when owners are being diligent about biosecurity. That’s why when an outbreak does occur, veterinarians might treat all of the horses at an event as potentially exposed, even those not showing signs of the disease.

“If you have protocols that apply to all horses,” says Pusterla, “even if such a horse enters the venue, you hope that the organism doesn’t spread.”

Those protocols usually include isolating any horse that shows signs of disease.

3. Don’t allow nose-to-nose contact.  

It’s hard not to let your horse touch noses with your friend’s horse as you wait for the next class. Your horse wants to be friendly, too. But that’s one of the easiest ways for disease to spread.

“No nosing at the in-gate, because you just have no idea where the other horse has been or what they’ve been exposed to,” says Scherrer. This extends to horses you don’t know, too, and to places on the grounds beyond the in-gate. “Most of the diseases that we see at shows are respiratory diseases, and they’re usually spread by nose-to-nose contact.”

Scherrer advises owners to contemplate the repercussions. Is it worth letting your horse be a pal if it risks months of layup and perhaps the spread of disease to your other horses back at home?

“Be careful at the wash rack,” Pusterla says. “Don’t share water. Don’t tie the horse outside the stall. And reduce the number of people who handle the horse.”

preventing equine disease spread

Pusterla adds that something as simple as washing your hands thoroughly after tending to one horse and before going on to the next can do a lot to reduce disease transmission.

Be sure to keep your horse’s vaccinations up to date, but he and Scherrer say not to assume your inoculated horse can’t get the disease.

“Vaccination is one of the many principles that reduce the risk of disease transmission, but that’s not the only one,” says Pusterla. “The reality is that a vaccine is an aid in disease prevention.”

Owners can become complacent and ignore other protocols if their horses are vaccinated, thinking they are “safe.”

For instance, “the flu/rhino vaccine lasts for a very short period,” says Scherrer. “If your horse gets that vaccination once or twice a year, there are many months in between where it may not be protecting your horse.  

“A lot of the vaccines may not completely prevent the disease,” she continues. “The idea is that they reduce the severity and the likelihood of getting the disease.”

Scherrer says horse owners who show frequently might vaccinate against influenza four times a year.

“Vaccine reactions are always possible, so some people may not want to vaccinate that often,” she says. “I completely understand that. My own horse had a vaccine reaction this year, and although most are quite mild, it’s a cost/risk balance.”

Take-Home Message

It is better to adhere stringently to a few core principles to avoid disease transmission than to try to remember everything that could possibly be done. Three of the most important are to choose your show venues based on their biosecurity protocols, monitor your horse regularly and diligently on the grounds, and limit direct and indirect contact between horses at the event. The more everybody works to keep their own horses safe from disease, the more we can minimize—and even eliminate—disease transmission and outbreaks.

“Everybody in the industry needs to be involved—the owners, the vets, the venue organizers,” says Pusterla. “If everybody contributes to disease prevention and applies practical biosecurity principles, one can definitively expect the risk of infection to be reduced.”