Lamb diagnosed with rabies in El Paso County

Lamb diagnosed with rabies in El Paso County

The following was distributed to Colorado veterinarians by the Colorado State Veterinarian’s Office on August 12, 2020. Click here to sign up to receive immediate updates from the Colorado State Veterinarian’s Office.

The Colorado Department of Agriculture has confirmed that a 3-month-old ram in El Paso county with neurologic signs tested positive for rabies at the Colorado Department of Public Health and Environment (CDPHE) laboratory.  This is the third case of rabies in domestic livestock in Colorado in 2020; a bull in Pueblo county and a goat in Yuma county were diagnosed with rabies earlier this year.

Case summary

The lamb had been sick and started displaying neurologic signs consistent with rabies around 08/04/2020.  Clinical signs included weight loss, hypersalivation, dysphagia, weakness, arched back and neck, star gazing, and recumbency.  The ram was euthanized and the area veterinary medical officer was contacted for sample collection and submission for rabies testing.  The lamb was confirmed positive for rabies on 08/07/2020.

The sheep on the premises had reportedly been attacked by coyotes on 08/02/2020.  Due to the prolonged incubation period of rabies, it is unlikely that the exposure to rabies happened during the coyote attack just days before.  The area veterinary medical officers are working to identify other possible exposures, including tracing back to when the lamb was purchased more than a month prior.  The lamb had a scrapie tag, which is an important component in disease tracing.

The remaining livestock on the premises were unvaccinated; all have since received rabies vaccinations and are under quarantine.

Information for veterinarians

Veterinarians are reminded that rabies and transmissible spongiform encephalopathies (TSEs) should be high on the differential list for any neurologic case in ruminants.  Veterinarians are required to report suspected cases to the State Veterinarian’s Office at 303-869-9130 or by contacting their area state or federal field veterinarian.

If a veterinarian has concerns about potential human exposures to rabies or questions regarding companion animal bites and exposures, they should contact their local public health department or the CDPHE at 303-692-2700.

Livestock vaccination  

All species of livestock are susceptible to rabies; cattle and horses are the most frequently reported infected livestock species.  All horses should be considered for vaccination against rabies.  Rabies is considered one of the core equine vaccinations in the AAEP guidelines.  Livestock that have frequent contact with humans (e.g. in petting zoos, fairs, and other public exhibitions) should be considered for vaccination against rabies, including species for which licensed vaccines are not available (extra-label use).  Consideration should also be given to vaccinating livestock that are particularly valuable.