College News


Equine HerpesVirus Confirmed at Cornell Hospital

In a joint release from the New York State Department of Agriculture & Markets and the College of Veterinary Medicine at Cornell University:

Private Barn and Equine Hospital Quarantined; State and Cornell Offer Advice to Horseowners

New York State Department of Agriculture and Markets’ animal health officials, along with veterinarians from the Equine Hospital at Cornell University are investigating two confirmed cases of Equine Herpesvirus 1 (EHV-1) in New York State. Both cases of EHV-1 were inpatients of the Equine Hospital at Cornell University, and could have potentially exposed 69 other horses. EHV-1 is a common viral infection of horses that is highly contagious and exhibits an array of symptoms, ranging from no clinical signs to neurological disorders.

New York State Veterinarian Dr. David Smith, said, “While a common virus in horses, we are taking this situation very seriously given the large number of horses that have potentially been exposed to a highly communicable and sometimes fatal disease. To date, no other horses have showed signs, nor tested positive for the virus. However, this serves as an excellent reminder to horse owners that they should always be cautious of introducing new horses with an unknown disease status.”

“We recognize the seriousness of the Equine Herpesvirus Type 1 and other infectious diseases,” said Dr. Alfonso Torres, Associate Dean of Public Policy at the New York State College of Veterinary Medicine at Cornell University. “Thanks to our surveillance systems and access to highly sensitive testing at the New York State Veterinary Diagnostic Laboratory, we were able to rapidly identify the infectious agent and implement appropriate actions immediately to prevent the spread of the infection.”

This incident involves two confirmed cases of EHV-1 in New York State. One was a one-day old foal that was admitted to the Equine Hospital on March 18. The foal died two days later of pneumonia, and tests revealed the presence of EHV-1 on March 25. During the same time, a gelding was being treated at the hospital for a spinal injury. It was discharged on March 22, but became severely ill and showed neurological symptoms after arriving back at its home farm. This horse tested positive for EHV-1 on March 30. The gelding is now recovering.

In response to the two confirmed cases, both the gelding’s farm and the Equine Hospital were quarantined immediately, restricting movement and access to animals at both facilities. Horses at both facilities are being monitored closely and having their temperatures taken twice daily. So far, no animals have exhibited a fever attributable to EHV-1, which would be an early warning of the virus. At the Hospital, PCR tests have also been completed for four consecutive days on all current patients. The PCR samples from all animals in the hospital are negative, indicating that no virus shedding is occurring.

As part of this on-going investigation, the Department is working to determine the source of the infection, as well as to identify and isolate potentially exposed horses. In doing so, Cornell has been contacting all referring veterinarians and the owners of 69 other equine patients that may have been exposed while at the Equine Hospital. The Department is also communicating with private veterinarians to provide information related to this situation, and is prepared to follow up on possible quarantines of trace-out barns of the 69 potentially exposed horses, if necessary. At this time, neither the Department, nor Cornell know of any other animals that have showed signs or tested positive for EHV-1 in association with this incident.

Nearly all horses in their lifetime will be exposed to EHV-1 at some point, and therefore it is difficult to detect as it takes on a wide range of manifestations, from a complete lack of clinical symptoms, to pneumonia, to abortion in mares, to full-blown fatal neurologic cases. The virus does not persist in the environment and is neutralized by hand soap, alcohol-based hand sanitizers, and sunlight. Transmission of the virus is mostly via direct contact with infected materials. EHV-1 does not affect humans or dogs, cats, cattle, sheep, goats, pigs or birds; although, alpacas and llamas can be affected.

If you are the owner or caretaker of a horse that has been at the Equine Hospital at Cornell on or after March 18, 2011 or that may have come in contact with a potentially exposed patient, the following guidelines are recommended:

  • Isolate your animal, if possible. It is always recommended that horses returning from veterinary hospitals be isolated for three weeks when possible.
  • Check your horse’s temperature twice a day for ten days. If the temperature is 102 degrees Fahrenheit or greater, contact your veterinarian immediately.
  • If you care to test your horse, consult your veterinarian. At this time, the preferred test is PCR analysis performed on nasal swab specimens.

Since March 30, 2011, the Equine Hospital at Cornell University has been quarantined. All movement of animals between the equine barns and other Cornell facilities is not permitted at this time, and the hospital is only accepting emergency cases. Out of an abundance of caution, the quarantine at the hospital will remain in effect through April 11.

For more information on EHV-1, visit the American Association of Equine Practitioners’ website or check USDA APHIS’ brochure on the virus.