Published Date: 2011-05-26 13:40:14
Subject: PRO/AH/EDR> Equine herpesvirus - North America (03): (USA)
Archive Number: 20110526.1607
EQUINE HERPESVIRUS- NORTH AMERICA (03): (USA)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Wed 25 May 2011
Source: The Salt Lake Tribune [edited]
A deadly horse virus outbreak that originated in Utah has prompted
the cancellation of competitions across the United States in an
attempt to contain the disease.
Late Wednesday [25 May 2011], state veterinarian Bruce King said 7
horses in Utah were infected with equine herpes virus-1 (EHV-1), and 8
horses were suspected having the disease; 2 horses were euthanized.
The animals were boarded at 4 private facilities in Box Elder, Davis,
Kane, and Utah counties.
There are 33 confirmed infection cases in 8 western states; 7 horses
have died. All but one of the cases were traced to the National
Cutting Horse Association's Western National Championships staged in
Ogden, Utah from 29 Apr to 8 May 2011, according to the US Department
The outbreak may not have run its course. More than 300 horses from
18 states were exposed to the virus at the Ogden competition and 689
horses were secondarily exposed. California reported the highest
number of exposures with 54 confirmed cases, followed by 36 cases in
Idaho, and 30 in Colorado. Texas logged the highest number of
potential exposures, with 323 horses, followed by 120 horses in
Oregon, and 68 in Colorado.
Although the disease cannot be transmitted to humans, it is extremely
contagious among horses. The virus can cause mild, flu like illnesses
in many cases, but some horses may become seriously or fatally ill
with respiratory or neurologic disease.
King is confident that the virus did not originate on the grounds of
the Golden Spike Event Center where the Ogden competition was staged.
His best guess is infected horses exhibiting no prior symptoms became
stressed while traveling to the show, causing the outbreak.
Horses can become stressed during competitions, as well, said [an
owner from] Sandy, who has entered cutting horse shows for the past 40
years. "Horses are smarter than we give them credit for," he said.
"They know why they're at the show. They know they have a job to do,
and that's stressful."
[He] entered 2 horses in the Ogden event. One became infected and has
since recovered. Although none of his 6 other horses is showing
symptoms, he takes their temperatures twice daily and has quarantined
his barn, as have others. Because the disease is so contagious, he
will not allow neighbors into his and he won't go into theirs.
Quarantines last at least 28 days.
[Another horse owner] competed in Ogden, but rather than boarding his
horses there, he traveled back to his Grantsville ranch at the end of
each day's events. Although none of his horses has symptoms, as a
precaution he monitors them daily, and doesn't allow anyone to use his
In still another precaution, the 22 000-member National Cutting Horse
Association has canceled all competitions for the time being,
impacting as many as 20 nationwide events. Other shows in Utah and
elsewhere have either been postponed or canceled. Officials are
telling owners to call ahead before attending an event to make sure
the competition hasn't been rescheduled.
"Right now, the less interaction with horses, the better off we are,"
said Dennie Dune, of Salt Lake City, and the group's past president.
"We not only have to protect our own horses, we also have a
responsibility to other equine disciplines sharing the same municipal
facilities in other competitions."
Competitions are big business. Owners say the price for a cutting
horse can range from USD 30 000 up to more than USD 1 million. The
American Horse Council says horse shows are a USD 39 billion annual
[Byline: Dawn House]
[The state of Utah and the other states reporting cases and exposures
to EHV can be located on the HealthMap/ProMED-mail interactive map at
http://healthmap.org/r/016l. - Sr.Tech.Ed.MJ]
[Owners are reminded this is a serious equine disease and the life of
your horse and other horses are at stake. Please do not travel with
your horse until this outbreak has indeed run its course. - Mod.TG]