The spread of a virus that sickened dozens of horses and spooked the equine community now appears to be subsiding.
The outbreak stemmed from the World Championship Barrel Racing Finals, held in Waco, Texas, in early November. Some of the horses that attended the event contracted a form of equine herpesvirus (EHV-1), according to the Texas Animal Health Commission.
The virus’ symptoms include a fever, cough and runny nose. But it can transform into a more dangerous disease called equine herpesvirus myeloencephalopathy (EHM), which affects the horse’s nervous system and can be fatal.
The Equine Disease Communication Center, which tracks outbreaks of horse diseases, confirmed 60 cases of EHV-1 or EHM linked to the Waco event across eight states – including Texas, Oklahoma, South Dakota and Louisiana. But there hasn’t been a new case reported since Dec. 3.
“That’s a good sign,” said Nathaniel White, a veterinarian based in Virginia and director of the center. “I’ll just say that it looks like it’s slowed down.”
White’s group only reports cases they’ve confirmed with state veterinarians. The information has helped horse owners like Laura Gardner of Parker, Texas make decisions for their animals.
Gardner is a barrel racer. She and her horse Seven attended the event in Waco, as well as another large barrel race less than two weeks later in Guthrie, Oklahoma – the annual Barrel Futurities of America World Championships.
Lots of riders attended both events. Rumors that horses who’d gone to Waco were getting sick started to spread while Gardner was at the Oklahoma competition. There was a “spooky” feeling at the arena, she said. She got a text from a friend with the news during the first day of the competition.
“By 3 o’clock, people were packing up and leaving,” Gardner said. “Literally everyone was packing up their gear, on the phone with veterinarians. I ended up calling my veterinarian too. And she said, ‘If there is a serious concern that there is EHV there, it is not worth the risk.’”
Gardner left. Organizers eventually canceled the event. And animal health specialists across the country worked to figure out just how far the virus had spread.
Tracing an outbreak
Lewis “Bud” Dinges started getting calls about sick horses roughly a week after the barrel races in Waco.
Dinges is executive director of the Texas Animal Health Commission, and the Texas state veterinarian. When the commission called the ill horses’ owners, it didn’t take long for him and his team to discover the Waco event was the common denominator. But that was only the start of their efforts.
Many of these horses had gone to other events after competing in Waco, and potentially exposed even more animals to the virus. The commission needed to contact all of these competitors, too. Dinges and his staff spent much of the days around Thanksgiving calling horse owners.
“We found I think 19 events that some of these horses had competed in,” Dinges said. “We've had like 2,200 trace horses out of the state of Texas from those 19 events. It was quite the undertaking for us, trying to contact these people and let them know what had happened.”
Dinges was in close contact with White from the Equine Disease Communications Center throughout this process, delivering the most up-to-date information possible to horse owners about the virus’ spread.
Owners needed to quarantine horses that had potentially been exposed to the virus for 21 days, take their animals’ temperature twice per day and submit the information to their state animal health authority.
Gardner, the Texas barrel racer, did not have enough room on her property to isolate her horse she had brought to recent competitions from the two she had not.
“I made the decision to just like, let her rip and the chips will fall where they may,” she said.
Other owners faced different challenges. Gardner said a friend feared her horse would kick her because of the twice-a-day anal thermometer readings.
The EHV-1 outbreak has also been an anxious time for horse owners whose animals didn’t recently attend events.
Chelsea Kaufman is a barrel racer from northeast Nebraska. Her daughter is starting to show horses through 4-H.
“When I heard about it, I got the same feeling that I kind of had when COVID started,” Kaufman said. “Which I know some people are probably like, well that's extreme. And I think I felt that way because my horses can't tell me what's wrong.”
Kaufman stopped going to a nearby indoor riding facility. She also moved her horses to a part of her property further from the road.
“You just never know. People see horses, they want to stop, they want to pet them. And it may seem extreme, but I was like ‘I don’t know where they’ve been,’” she said.
Humans and horses don’t spread EHV between them. But a person who’s been handling equipment of an infected horse could potentially get other horses sick. The virus doesn’t infect humans, Dinges of the Texas Animal Health Commission said.
Kaufman kept a close eye on the Facebook pages of Texas veterinarians, and called her personal vet shortly after news of the Waco outbreak broke to see if they were aware of it.
“They weren’t, which is good because it means they didn’t get any cases,” Kaufman said. “But they were also thankful I brought it to them.”
Assessing risk
The EHV outbreak hit during an especially busy time in the horse world. The risk of the virus canceled or delayed a number of rodeos, races and other events.
In Kansas, the Prairie Circuit Finals Rodeo in Mulvane was canceled in late November, as was the Old-Fashioned Christmas Parade in Lawrence at the beginning of the month. Various events in Texas, Oklahoma, Nevada and Colorado were also called off.
Others proceeded as planned or with modifications. The National Finals Rodeo, a major event in Las Vegas, went forward with stricter biosecurity measures.
Justine Staten, executive director of the Kansas Horse Council, said the level of risk depends on the type of event.
“If my horse had not been anywhere around [potentially sick horses] and I just want to go trail ride, am I at risk? Highly unlikely,” Staten said. “But if my horse is involved in some of these same sports that those horses are in, I would be at higher alert than somebody who’s not in that same circle.”
Staten tried to convince organizers of the Christmas parade in Lawrence to go forward with the event, but to no avail.
“It’s the largest horse-drawn parade that we know of in the Midwest, and it’s got such a wonderful history to it,” she said. “I was really hoping that they wouldn’t cancel because most of the horses that participate in that parade, let’s face it, they’re not barrel racers.”
White, the veterinarian and director of the Equine Disease Communication Center, didn’t think that canceling certain events was “overkill.”
White stressed that even though it’s been more than two weeks without a new confirmed EHV case, there are still horses out there that could develop a sickness from the outbreak, since symptoms can take 21 days to show themselves.
“It’s a difficult thing, because you don’t want to shut down a show. On the other hand, if there is a risk … then it’s smart not to hold that event,” he said. “We have to be very careful with it.”
The vaccine for EHV-1 does not prevent the virus from morphing into EHM, the more harmful neurologic disease. But it can help horses from spreading the virus to each other. Not all rodeos require horses to have it, however.
In general though, White said that biosecurity has improved over his 30-plus years in equine medicine.
“I think people are much more aware of [temperature checking] their horses before they get on the truck to go to the show, make sure the horse is healthy, not having horses go nose-to-nose,” he said. “Not sharing equipment, not drinking out of the same water trough, anything common sense like that.”
Gardner, the barrel racer from Texas, plans to take her horses off her own property in small steps.
“I would probably feel comfortable taking them to a small local show maybe next week,” she said. “But I’m not planning on going anywhere big until January.”
This story was produced in partnership with Harvest Public Media, a collaboration of public media newsrooms in the Midwest and Great Plains. It reports on food systems, agriculture and rural issues.
