11/20/2025
The Ranch Docs Team- specifically our equine veterinarians- Dr. Mohr, Dr. Oviatt, Dr. Booth, Dr. Whitelaw and Dr. Blais would like to provide an Important EHV-1/ EHM Update:
We have been receiving calls regarding the respiratory Equine Herpesvirus (EHV-1) and the associated neurological Equine Herpesvirus Myeloencephalopathy (EHM) virus outbreak throughout North America. There have been several confirmed cases in Texas and Oklahoma and now one confirmed case in the Red Deer area.
What horses are most at risk?:
Any horses that have travelled recently or been to large events
Any horses that have had contact with other horses from the affected region
Unvaccinated horses
Younger horses (less than 2) are more likely to develop respiratory disease
Older horses are more likely to develop EHM and neurological signs
Pregnant mares in the last trimester of pregnancy
Clinical Signs to monitor for:
Respiratory Signs- coughing, nasal discharge, fever (normal temperature 37.2-38.6 °C/ 99-101.5 °F)
Neurological Signs EHM- incoordination, hind-limb and tail weakness, inability to stand, dribbling urine
Other signs- late term abortion in mares
What you can do:
Quarantine any horses and property that have had a potential exposure
All horses have the potential to be carriers so avoid travel and events until we have more information
Continued monitoring of temperature
Practice proper biosecurity and avoid sharing tack and water buckets between horses
Make sure horses are up to date on vaccines, and pregnant mares receive the Pneumobort vaccine at months 5,7 and 9 of pregnancy
If your horse develops clinical signs and/or has travelled to or has been exposed to other horses who have travelled to the affected areas (Texas, Oklahoma, Red Deer Alberta) please
Call us immediately (403) 327-4658
Isolate horse and other exposed horses
Continued monitoring for symptoms, temperature and practicing biosecurity
Please remember that transparency with your veterinarian about potential exposure is crucial as horses with potential exposures pose a risk not just on farm but also to veterinary facilities.
Please call the clinic with any questions or concerns or if you are wanting more information (403) 327-4658
https://aaep.org/wp-content/uploads/2021/02/Equine-Herpesvirus-EHV-1-and-EHV-4-Guidelines-final.pdf