A horse was recently referred to the MSU Veterinary Medical Center (VMC) from Washtenaw County by its primary veterinarian for evaluation of recent onset of neurologic disease and urinary incontinence. Fortunately, the horse’s primary veterinarian recognized that these signs could be consistent with a highly contagious disease and immediately referred the animal to the MSU VMC.
Based on the history, Drs. Tara Shearer and Lisanne Gallant recognized that the signs could be indicative of Equine Herpevirus-1 (EHV-1)—specifically the form of the virus which causes a condition known as Equine Herpes Myelopathy (EHM) in which the virus infects and damages the spinal cord. Consequently, the horse was admitted directly to the Pegasus Critical Care Center for Horses, MSU’s state-of-the-art isolation facility for large animal patients. After examining the patient and starting emergency treatment, Drs. Shearer and Gallant collected the appropriate samples for the MSU Veterinary Diagnostic Laboratory (VDL) to run diagnostic tests. The VDL ran these tests on a Sunday on an emergency basis to confirm the suspected diagnosis. In less than 24 hours, the results were available. The horse was indeed positive for EHV-1/EHM.
The Pegasus Critical Care Center at MSU VMC is the only facility in the state of Michigan that can house large animals in individual isolation stalls. It has ten completely contained stalls, each with individual entry ways and ventilation systems, which prevents cross contamination between adjacent stalls. Further, the Pegasus Center is separated from the main Veterinary Medical Center by a large parking lot so there is no risk that patients in the main hospital would be exposed to potentially contagious diseases afflicting horses in the Pegasus Center.
Because of the quick action of the horse’s primary veterinarian, the diagnostic acumen of Drs. Shearer and Gallant, and the rapid diagnostic testing provided by the VDL, potential spread of this contagious virus was mitigated. Also because of the potential for this virus to cause an outbreak of EHV-1/EHM in other horses at the facility at which the horse was stabled, Drs. Shearer and Gallant also contacted the state regulatory veterinarian at the Michigan Department of Agriculture and Rural Development (MDARD) to report their suspected diagnosis. By the time the test results confirmed the EHV-1/EHM diagnosis, MDARD had already sent a state veterinarian to the training/boarding facility, and a portion of that facility was immediately quarantined.
EHV-1 is spread by aerosolization of nasal secretions within the stall and stable areas, direct horse-to-horse contact, as well as via contaminated hands, equipment, and tack. In addition to the ability for this virus to affect multiple animals, an outbreak of EHV-1 can have devastating economic impact for horse owners, training/boarding facilities, and the horse racing/showing industries in particular.
The teamwork between the primary veterinarian, Drs. Shearer and Gallant, the VDL, and MDARD allowed prompt isolation of the horse, rapid diagnostic testing/results, and quick implementation of a quarantine in order to maximize containment of this virus.