On April 12, 2018 the Wyoming Livestock Board (WLB) barrel racing horse in Laramie County suspected of having rabies was admitted to CSU Veterinary hospital with progressive neurologic disease affecting both hind and front limbs as well as the cranial nerves. The horse was recumbent and euthanized for humane reasons.
Testing for rabies was negative on the April 13.
The horse owner was contacted and because EHM had not yet been ruled in or out, they were advised to impose a self-quarantine and implement enhanced monitoring of each horse on the premises to include at least twice daily recording of rectal temperatures with any suspect cases reported immediately.
On Monday, April 23, CSU reported to the WLSB that brain tissue was suspect on PCR for EHV-1 wild type and that histopathology of the spinal cord was consistent with EHM. On Tuesday, April 24, CSU reported to the WLB that nasal swabs that had been collected on admission and held were test positive on PCR for EHV-1 wild type. This confirmed EHM and allowed an official quarantine to be placed on the premises, which had already been meeting the conditions of such on a voluntary basis since the April 12.
With no further cases being suspected during the 14 days from last exposure and because of diligent monitoring, the quarantine was released on April 26.
The WLB has been working closely with the Colorado Department of Agriculture on this and other cases and the source of this infection is currently unknown.
