Our Experience with EHV-1
In mid-March 2008, two horses at Willow Ridge Stables developed neurologic symptoms.
In the week prior to that, horseowners had noticed an unusual trend of fevers and stocked-up legs that lasted for a day or two but resolved. The cause of the symptoms was soon suspected to be some form of viral illness, and later tests confirmed Equine Herpes Virus 1, which sometimes causes a range of neurologic symptoms.
With the guidance of the Western College of Veterinary Medicine at the University of Saskatchewan, biosecurity measures were put in place to contain the infection.
Biosecurity measures included:
Initially it was suspected the virus had not spread to the horses boarded outside, and movement of horses between indoor and outdoor was limited at first, however it soon became apparent that the outdoor horses had already been exposed and the restriction was lifted.
At the suggestion of the WCVM, horseowners were asked to monitor their own horses for any signs of the viral illness (fevers, stocked-up legs, runny nasal discharge, low energy) as well as to watch closely for any signs of neurological changes.
Our thanks...
We were fortunate to have had such tremendous support from the WCVM. Dr. Kristen Poirier and Dr. Nathalie Tokateloff (Field Services) in particular were here for us around the clock when we needed them most. They seemed to work tirelessly, demonstrating competence and real dedication in treating our horses, providing education, and keeping us all informed.
The support and understanding from the boarders was also outstanding. We really appreciated all of their help in assisting with the care of the horses, ranging from helping to quickly prepare deep-bedded stalls, to night checks at 4am, to assisting veterinarians with swabs and other care. Everyone was excellent about adhering to biosecurity protocols, despite the considerable disruption to their normal activities. Boarders were responsible for the creation of a database to monitor horses' signs and symptoms, and keeping the website current with updates from the vets.
Quarantine ended: April 27 2008
We are happy to report that while we did go through a very intense period, with so many horses to monitor, the majority of the 85 horses on the property at the time either developed no illness at all or only mild symptoms, such as a fever, with no progression to neurological illness. Of the horses that did show varying degrees of neurological signs, all are moving towards recovery and most have already resumed normal activities.
As of April 27 2008, we completed our voluntary quarantine of the facility, after having four weeks without any new cases of even febrile illness. A number of horses who were present during the outbreak have now returned to summer homes or other boarding or training facilities. The two pregnant mares have been relocated to a private acreage to await foaling. It is fortunate that the virus does not live long in the environment, but as a precaution we are in the process of pressure-washing and disinfecting the barns.
With a few precautions, it appears to be possible to limit the spread of this virus. Many of us also have horses at home and, following the aforementioned biosecurity protocols, were going back and forth between them with no spread of the virus that we are aware of.
More information:
This page is the information that was prepared, by boarders for boarders, during the EHV-1 outbreak at Willow Ridge Stables. It is not a definitive source about EHV-1, its diagnosis, treatment, or outcomes.
Further information about EHV-1 may be obtained from the sources at WCVM, such as Dr.Katharina Lohmann, or from your veterinarian.
We recommend reading the excellent article on the SHF website entitled "EHV Contained" which summarizes a public seminar given by Dr. Hugh Townsend (Professor of Veterinary Microbiology, WCVM).
The Alberta Equestrian Federation has prepared a booklet on Biosecurity Measures. Read more.