EHV-1 Outbreak: State Veterinarians Monitoring Closely

Tue, Jul 12, 2011


by: Erica Larson, News Editor
May 18 2011, Article # 18262

[UPDATE] The USDA has said that the virus/out-break is over and has been containes. (Source DVM Mag.)

The number of horses affected by the neurologic equine herpesvirus-1 (EHV-1)
outbreak in the western United States and Canada continues to rise. Since health
officials identified the virus as stemming from involvement with the National
Cutting Horse Association (NCHA) Western National Championship competition, held
April 28-May 8 in Ogden, Utah, the number of confirmed cases has reached the
double digits.

Equine herpesvirus is highly contagious and can cause a variety of ailments
in horses, including rhinopneumonitis (a respiratory disease mostly of young
horses), abortion in broodmares, and myeloencephalopathy (evident in the
neurologic form). The virus is not transmissible to humans. Clinical signs of
the neurologic EHV-1 form include fever, ataxia (incoordination), weakness or
paralysis of the hind limbs, and incontinence. The virus is generally passed
from horse to horse via aerosol transmission (when affected animals
sneeze/cough) and contact with nasal secretions.

State and provincial veterinarians are keeping close tabs on the number of
confirmed and suspected EHV-1 cases. Since there is no centralized data
reporting system, case counts are based on reports from individual states
(although the Veterinary Infection Control Society has been collecting information regarding suspected and confirmed

Utah State Veterinarian, Bruce L. King, DVM, said, “At this
point we have had no confirmed cases of EHV-1 in Utah since the NCHA show that
was held in Ogden. We do have some suspect horses that were at the show that
laboratory confirmation is pending.”

California now has 10 confirmed cases of EHV-1, according to a
news release from the California Department of Food and Agriculture. A total of
54 horses from California competed at the NCHA championships.

Canada veterinarians also are on the lookout for cases. “Our
office has been notified of one case of (neurologic) EHV-1 in the province of
Alberta,” said Chief Provincial Veterinarian Gerald Hauer, DVM. “The horse has
been attended by a veterinarian, is isolated, and is recovering.”

Idaho agriculture released a statement indicating that two
horses were euthanized that exhibited clinical signs consistent with neurologic
EHV-1 and “several others” are under veterinary care, but there have been no
confirmed cases.

Washington saw its first EHV-1-positive case discharged from
Washington State University’s (WSU) Veterinary Teaching Hospital on May 13.
Today Debra C. Sellon, DVM, PhD, Dipl. ACVIM, a professor of equine medicine at
WSU, reported that since the discharge all PCR diagnostic tests run on hospital
patients have been negative, and the university hospital remains under

Today (May 18) a second case of EHV-1 was confirmed. The horse presented with
neurologic signs and was taken to Pilchuck Veterinary Hospital (PVH)
in Snohomish. Attending veterinarian Wendy Mollat, DVM, Dipl. ACVIM, said in a
press release issued by the hospital that upon presentation to PVH, “the horse
was immediately admitted to our designated equine isolation facility and has not
been allowed direct or indirect contact with our general equine population. The
horse is clinically stable and will remain hospitalized until confirmed to be no
longer shedding the virus.”

Oregon confirmed its first case of EHV-1 today when
one horse that attended the NCHA competition produced a positive test. A press
release issued by the state Department of Agriculture indicated there are no
travel restrictions on non-exposed horses at this time.

New Mexico Livestock Board officials issued a press release
from indicating that there are two suspected EHV-1 cases in that state, however
both horses are currently under quarantine and veterinary treatment. There were
no confirmed cases at press time. Additionally, all New Mexico horses that
attended the NCHA show are under voluntary quarantine at their regular barns and
are being monitored for signs of disease.

Currently Unaffected States on High Alert

Fortunately, authorities in some Western states have not received reports of
any EHV-1 positive horses. Nonetheless, veterinarians and horse owners remain on
high alert and are taking precautionary steps to prevent the spread of any
possible disease.

“At this time there are no EHV-1 positive or suspect horses in Wyoming that
we are aware of,” said State Veterinarian Jim Logan, DVM. “We do know that there
were some horses that attended the Ogden event and returned to Wyoming. All of
these animals have been accounted for, are isolated, and under movement
restriction and observation by veterinarians. None have shown any clinical signs
to date.”

The Texas Animal Health Commission (TAHC) issued a statement yesterday (May
17) indicating that there are no EHV-1 positive horses in the state currently,
and the commission “has no plans to change entry requirements for equine animals
or to cancel any equine events at the present time.”

Both North and South Dakota state veterinarians–Susan J. Keller, DVM, and
Dustin Oedekoven, DVM, respectively–said that EHV-1 has not been confirmed in
their states. Oedekoven added that none of the horses that attended the Ogden
show from South Dakota were showing any clinical signs of the disease.

Likewise, State Veterinarian Phil LaRussa, DVM, said Nevada is free of EHV-1
at present.

Shifting Transportation Requirements

The Colorado Department of Agriculture issued a press release yesterday,
introducing new travel requirements for any horses entering the state.

Horse owners must obtain a permit to enter the state in addition to
presenting the standard health certificate (issued within 30 days prior to
entry) and a proof of a current negative Coggins test.

“Horse owners who wish to bring their horse into Colorado must first call
their veterinarian,” the department press release stated. “That veterinarian can
then contact the Colorado Department of Agriculture’s State Veterinarian’s
Office at 303/239-4161 and request a permit number. That number would then be
included on the health certificate.”

“We are considering all of our options for protecting Colorado’s horse
industry,” State Veterinarian Keith Roehr, DVM, said in the press release. “At
this point, we do not believe it’s necessary to stop horses from entering the
state but we need to be able to know where those horses are coming from and
where they are going; trace-back is a vital part of disease control.”

Yesterday the NCHA released a statement on its website indicating that while
the organization was not requiring show producers to cancel or reschedule shows,
it urged these individuals to make horse health the No. 1 priority: “While the
NCHA is at present not mandating cancellation of all shows nationwide, we do
strongly urge all show producer(s) to consider the possible horse health risks
of conducting an event until the extent of the virus can be determined and

Additionally, the American Paint Horse Association released a list
of shows canceled
due to the EHV-1 outbreak on the organization’s website.

5 Responses to “EHV-1 Outbreak: State Veterinarians Monitoring Closely”

  1. Richard Says:

    It is important for all of us to do our part.


  2. Easy Recipes Chicken Says:

    Good article! Keep it up!


  3. Richard Says:

    Please do your part to help stop this outbreak.


  4. Herpes Symptoms Says:

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  5. Janey Dohrman Says:

    Hey, nice entry! I will keep reading your blog 😉


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