11/19/2025
UPDATE: there has been 1 confirmed case of EHV in Larimer County. The horse was at the barrel racing event in Waco, TX. It is in isolation. There remains to be low risk for all CO horses who have not traveled outside the state or had exposure to horses who traveled to either the Waco event or OK event in Guthrie.
It is important to note that there are no cases in Colorado at this time. Information surrounding the outbreak is still being analyzed.
IF you traveled to the WPRA event in Waco Nov. 5-9th or traveled to BFR in OK (canceled) and are returning home you must isolate your horses for 21 days and monitor them for any signs of illness.
Horses who have not had any exposure to outside horses or traveled outside the state should be at low risk but it is still recommended to monitor your horses twice a day and practice proper biosecurity.
Vaccination with Flu/Rhino is always recommended for all horses including fall boosters to help protect against EHV. That being said there is no proven vaccine that is effective at preventing the neurologic form of EHV that causes EHM.
IF your horse is displaying any signs of EHV or illness please reach out right away to have them evaluated.nnwr yot tesdteieri
What is Equine Herpesvirus (EHV)?
You've probably heard it called Rhinopneumonitis, a respiratory tract disease that results in "snotty noses," but EHV is more than that. Depending on the strain, this virus can also cause abortion in broodmares, and equine herpesvirus myeloencephalopathy (EHM) — the often-deadly neurologic form of the disease.
Because EHV is endemic in many equine populations, most mature horses have developed some immunity through repeated natural infection. However, they remain a source of infection for other susceptible horses, like weaned foals and yearlings, who usually display symptoms of the respiratory form of the disease in autumn and winter. Performance and show horses are also more vulnerable to the disease, as they commingle with unfamiliar equines in close quarters while under stress from travel and competition.
Proper biosecurity protocols can help reduce EHV outbreaks and other disease transmission. A variety of vaccines are also available for protection against both the respiratory and abortive form of the disease, but there is no equine licensed vaccine at this time that has a label claim for protection against the neurologic form (EHM).
Consult your primary equine veterinarian to learn more about this disease and work with them to determine the optimal vaccine protocol for your horses.
You can learn more about all three forms on the Equine Disease Communication Center's website here: https://equinediseasecc.org/infectious-diseases
