In contrast to a recently published study on EHV-1, the late George Allen, PhD, a University of Kentucky Gluck Equine Research Center scientist, described a model to study equine herpesvirus-1 (EHV-1) and myeloencephalopathy and identified major risk factors critical to experimental reproduction of this syndrome.

In his article, published in December 2008, Allen explained that despite the discovery of an important genetic mutation among strains of EHV-1 frequently implicated in outbreaks of myeloencephalopathy, the risk factors associated with this disease remained “largely undefined.” EHV-1-induced myeloencephalopathy is of interest to the equine community due to the increasing incidence, frequent severity of disease, and high case fatality rate.

Thirty-six female horses group by age were employed in the study. Twelve horses greater than 20 years of age were inoculated intranasally with an abortogenic strain of EHV-1 (lacking the specific genetic mutation associated with neurologic disease) while the remaining 24 horses comprising 2-12 years of age and 12-15 years of age were inoculated with the mutant or neuropathogenic strain of the virus.

Inoculation was achieved using 10 million plaque-forming units of EHV-1 administered intranasally with a fenestrated rubber catheter. Horses were monitored daily and blood and nasopharyngeal secretions were collected frequently over the first 21 days of the study