Thursday, May 19, 2011

AAEP release on EHV-1 reporting

The American Association of Equine Practicioners (AAEP) has released the following regarding reporting of any suspect EHV-1 exposed horses:

American Horse Council and AAEP work with USDA to Facilitate Coordination of
EHV-1 and EHM Case Reporting
Horses exposed to the Equine Herpes Virus (EHV-1) based on attending an event held in Utah will now be monitored through a national case reporting system.  In addition, a guidance document was sent to State Animal Health Officials and Area Veterinarians in Charge (AVIC) in each state on Tuesday, May 17, 2011, courtesy of the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS), Veterinary Service (VS).
In response to confirmed cases of Equine Herpes Virus (EHV-1) and Equine Herpes Virus Myeloencephalopathy (EHM) in horses that attended a cutting horse event in Ogden, Utah held from April 29 to May 8, 2011, the American Horse Council (AHC) and the American Association of Equine Practitioners (AAEP) contacted the USDA:APHIS:VS and requested federal coordination for data collection, dissemination, and communication efforts among state and federal veterinarians. The purpose of collecting this data is to protect the health of horses and mitigate the economic implications of further EHV-1 transmission to horses not yet affected.
In response, USDA:APHIS:VS has reached out to State Animal Health Officials, federal Area-Veterinarians-In-Charge (AVICs) and private practitioners to collect current information on the EHV-1 disease incident and develop a coordinated response among state, federal and industry partners.  The full scope of the current EHV-1 situation and a complete accounting for the number of horses affected and/or exposed is underway.
"We want to applaud the quick response and efforts of the USDA:APHIS:VS," said William A. Moyer, DVM, 2011 AAEP president. "Having the support and coordination of this effort by the USDA:APHIS:VS working in collaboration with State Animal Health Officials, will be key in providing accurate and timely information to the equine and veterinary communities during this outbreak."
"USDA can play a critical and timely role in collecting, verifying, and disseminating accurate information to state animal health officials and industry partners," said Jay Hickey, President of the American Horse Council.  "These efforts are essential to mitigating the health and economic implications of this current EHV-1 situation. Misinformation can often be an epidemic in and of itself.  This latest disease incident only underscores the importance of implementing a pro-active national equine health program."
USDA and State Animal Health Officials have initiated an investigation and incident response effort.  The USDA plans to release the initial report through summarization of information provided by the State Animal Health Officials and AVIC's including the number of horses suspected and confirmed as EHV-1 cases and EHM cases along with fatalities in the coming days. The USDA will update and release future reports on the current EHV-1 outbreak on a weekly basis.  If the current incident results in wide-spread exposure or a large influx of infected horses, the USDA will provide that information as it becomes available.
Practitioners are encouraged to notify their State Animal Health Official of suspect or confirmed cases of EHV-1 and EHM.  The State Animal Health Officials can assist with guidelines on diagnostic testing and management to reduce risk of spread of EHV-1.
There have been numerous scientific articles citing a wide variation in the number of suspect and confirmed cases of the EHV-1 and the neurological form of the disease (EHM) in horses.  This large disparity in reported information underscores the importance of allowing USDA and State Animal Health Officials to collect data, based on the use of consistent case definitions, to then verify information gathered and disseminate factual summary information.
Until state and federal animal health officials are able to gather, verify and disseminate accurate information on the scope of the current incident, it is critical for individual horse owners and organizations to undertake appropriate and responsible actions to mitigate the welfare and economic implications of potential future transmissions.
At the time this release was issued, only Colorado and Wyoming had implemented enhanced state entry requirements in response to the on-going EHV-1 disease situation.
Additionally, if you anticipate transporting your horse across state lines it is recommended you contact each respective state/provincial veterinarian's office prior to departure to determine if there are any restrictions or enhanced entry requirements due to the current EHV-1 incident.  To find your state or provincial animal health office, visit
In the interim, the AHC and AAEP stress the importance of responsible ownership practices and informed communication among industry organizations.  Please visit the AAEP's website at for additional information on these diseases, as well as updated horse owner and veterinary resources including an FAQ feature about the diseases, biosecurity recommendations, updates from various states and more.
The American Association of Equine Practitioners, headquartered in Lexington, Ky., was founded in 1954 as a non-profit organization dedicated to the health and welfare of the horse.  Currently, the AAEP reaches more than 5 million horse owners through its over 10,000 members worldwide and is actively involved in ethics issues, practice management, research and continuing education in the equine veterinary profession and horse industry.
 As the national association representing all segments of the horse industry in Washington, D.C., the American Horse Council works daily to represent equine interests and opportunities. Organized in 1969, the AHC promotes and protects the industry by communicating with Congress, federal agencies, the media and the industry on behalf of all horse related interests each and every day.
The AHC is member supported by individuals and organizations representing virtually every facet of the horse world from owners, breeders, veterinarians, farriers, breed registries and horsemen's associations to horse shows, race tracks, rodeos, commercial suppliers and state horse councils.

The I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

EHV-1 vaccination

The question of the day seems to be about vaccination and EHV-1.  Here is my opinion:
There are two types of EHV-1 virus.  The first is the wild type EHV-1, which causes upper respiratory disease, abortion, and rarely, neurologic disease. The second is  neuropathogenic EHV-1, which is the virus identified in horses from the Ogden event.  This type has a genetic mutation that makes it much better at attacking the central nervous system, and therefore much more likely to cause neurologic disease, or EHVM (equine herpes virus myeloencephalitis).

 There is no vaccine known to protect against  EHVM.

The EHV-1 vaccines currently on the market have been shown to decrease the incidence of disease and the severity of signs in horses that get sick with wild type EHV-1.  There may be some cross-protection with these vaccines against infection with neuropathogenic EHV-1, but only if the horse is vaccinated at least 2 weeks prior to exposure to the neuropathogenic EHV-1, and even then this protection has not been proven.  Many horses currently clinically ill with EHVM were vaccinated against wild type EHV-1. Unfortunately, the interaction of the vaccine reaction and the neuropathogenic EHV-1 is very complex and not well understood.  If the vaccine is administered very close in time to exposure to the neuropathogenic EHV-1, vaccination may actually be harmful.

Based on this, here is my recommendation:
If there is any risk that your horse may have been exposed to neuropathogenic EHV-1 (the virus responsible for the current outbreak) do NOT vaccinate your horse. 
If there is NO risk that your horse has been exposed, and your horse is being housed in a closed facility so that there will be no new horses introduced within the next 2 weeks,  and your horse has not received a flurhino shot this year, then it is safe to proceed with routine spring vaccination.

I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

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