Kentucky Issues EHV-1 Perspective and Position Update
On Mar. 7, the state veterinarian’s office at the Kentucky Department of Agriculture (KDA) issued a Perspective and Position Update related to this year’s occurrences of equine herpesvirus-1 (EHV-1).

“In the past seven days we have learned of multiple occurrences of EHV-1 impacting equine events throughout the world,” read a statement sent by Rusty Ford, equine operations consultant for the state’s veterinarian’s office. “Additionally, as we are coming to the time of year that we historically see an increase in movement of equine exhibition and racing stock into Kentucky, I want to remind all associated parties that mitigating risk of disease introduction is a shared responsibility that requires commitment from each individual exhibitor, trainer, event managers, facility operators, veterinarians, and animal health officials.”

The statement goes on to say that venue and show managers for events to be held in Kentucky should review their biosecurity protocols and elevate their responses to minimize direct contact between horses via shared water, feed supplies, and equipment, as well as in common areas.

“The goal of a biosecurity plan is to prevent the transmission of infectious agents among individuals and the components of a successful program will include cooperation of management, facility layout, decontamination, and when applicable, immunization,” the update continues.

KDA encourages managers as well as exhibitors to download and implement American Association of Equine Practitioners (AAEP) biosecurity guidelines online.

“I did earlier today (Mar. 7) speak with the Florida State Veterinarian overseeing the EHV-1 investigation and management of the disease incident in Ocala, Florida,” said Ford. “As of today, there continues to be a single barn on the Ocala facility with EHV-1 cases confirmed by diagnostic testing. The barn remains under quarantine and activity on the premises is being monitored by animal health officials. Equines presenting with evidence or suspicion of illness are being isolated and tested.”

EHV 101

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and equine herpesvirus myeloencephalitis (EHM, the neurologic form).

In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months) but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with EHM usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

Herpesvirus is easily spread by nose-to-nose or close contact with an infectious horse; sharing contaminated equipment including bits, buckets, and towels; or clothing, hands, or equipment of people who have recently had contact with an infectious horse. Routine biosecurity measures, including hygiene and basic cleaning and disinfection practices, should be in place at all times to help prevent disease spread.

Current EHV-1 vaccines might reduce viral shedding but are not protective against the neurologic form of the disease. Implementing routine biosecurity practices is the best way to minimize viral spread, and the best method of disease control is disease prevention.