Published Date: 2011-05-24 10:28:21
Subject: PRO/AH/EDR> Equine herpesvirus - North America (02): (Canada, USA)
Archive Number: 20110524.1573
EQUINE HERPESVIRUS - NORTH AMERICA (02): (CANADA, USA)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: 21 May 2011
Source: Plumas News [edited]
Equine herpes virus confirmed in Plumas County
State officials reported this afternoon that California has 2 more
confirmed cases of equine herpes myeloencephalopathy (EHM), including
one case in Plumas County. That brings the total number for the state
Local sources say the Plumas case involves a horse in the Vinton area
that attended the National Cutting Horse Association's Western
National Championships held 30 Apr - 8 May 2011 in Ogden, Utah, where
officials believe the outbreak began. All of the confirmed cases in
California are in horses that attended this event.
A total of 6 of the positive horses display neurological signs, but
the other cases have only been febrile, said the California Department
of Food and Agriculture (CDFA). All confirmed cases in California are
under state quarantine.
One confirmed positive horse was euthanized after showing severe
neurological signs associated with the disease while at the Kern
County Cutting Horse Event 13 May 2011 in Bakersfield, state officials
A suspected case is currently under investigation. This horse did not
attend the Ogden event, but did participate 5-12 May 2011 in the
Rancheros Vistadores ride in Santa Ynez.
The confirmed cases in California are in the following 10 counties:
Amador, 1; Glenn, 2; Kern, 2; Los Angeles, 1; Marin, 1; Napa, 1;
Placer, 2; Plumas, 1; Shasta, 1; and Stanislaus, 3.
EHM is highly contagious, especially among younger horses that travel
a lot and intermingle with other young horses, according to info from
the CDFA. Signs can range from respiratory illness to severe
neurological disease. Signs may include a fever over 102 degrees F,
lethargy, decreased appetite and neurological symptoms such as lack of
coordination, hind limb weakness and inability to stand.
Local horse owners are advised not to travel with their horses.
[Byline: Delaine Fragnoli]
Communicated by :
Date: 23 May 2011
Source: Herald Extra
Utah horse euthanized
A Utah County horse has become the 1st to die in the state as the
result of an outbreak of equine herpes.
The Utah Department of Agriculture and Food says the horse was
euthanized Saturday [21 May 2011] after it was unable to stand up in a
So far, 6 other horses in Utah also have tested positive for equine
herpes virus-1: 4 are in Utah County and one each are in Weber and
Kane counties. The facilities where they are housed are under
quarantine for at least 4 weeks.
The highly contagious virus had as of Saturday infected at least 34
horses in 9 states and Canada, and killed at least 7 horses after an
Ogden equine event earlier this month.
Healthmap alert via ProMED-mail
[Equine herpes myeloencephalopathy (EHM) is another name for the
neurological form of equine herpesvirus. Neurological signs appear as
a result of damage to the blood vessels in the brain and the spinal
cord associated with the virus.
To date, 9 EHVs have been identified worldwide. 3 of these -- EHV-1,
EHV-3, and EHV-4 -- pose the most serious health risks for
domesticated horses and can have significant economic impacts on the
U.S. equine industry.
EHV-1: Can cause 4 manifestations of disease in horses, including a
neurological form, respiratory disease, abortion, and neonatal death.
EHM is most often due to mutant or neuropathogenic strains of EHV-1,
so called because of a particular mutation in the genome.
EHV-3: Causes a venereal disease called equine coital exanthema that
affects the external genitalia.
EHV-4: Causes a nonfatal upper respiratory tract disease in foals and
is uncommonly associated with abortion and rarely with neurologic
Horses may appear normal and yet be shedding virus in their
secretions. This can be spread to other horses. Part of the reason
that officials are recommending people remain at home with their
horses is that the virus may be reactivated induced by the stress of
As EHV can result in death of the animal, it seems far better to give
up on the proposed event than to lose the animal to death.
Signs of EHM/EHV include: Fever preceding neurologic signs (either in
a horse diagnosed with EHM or in horses that have been exposed to a
horse diagnosed with EHM), decreased coordination, urine dribbling,
loss of tail tone, hind limb weakness, leaning against a wall or fence
to maintain balance, lethargy, and inability to rise.
The standard form of care for EHM is primarily supportive. Treatments
may include intravenous fluids or anti-inflammatory drugs. Antibiotics
may be used to treat a secondary bacterial infection if one develops;
however, antibiotics have no effect on the equine herpesvirus itself.
Antiviral drugs have also been used to treat EHM cases. Research on
the efficacy of these drugs, their cost effectiveness, and the optimal
dosing regimen for EHM is still underway.
Portions of this comment have been extracted from:
This is an excellent publication from the folks in APHIS. It is easy
to read and may be helpful to many who find they are dealing with
animals encountering this disease. - Mod.TG
The interactive HealthMap/ProMED map for California is available at:
http://healthmap.org/r/00aj. The interactive HealthMap/ProMED map
for Utah is available at:
http://healthmap.org/r/016l - CopyEd.EJP]