Skip to main content

Idaho Fish and Game


Challis ranchers team up with biologists to keep bighorn sheep healthy


For over a century bighorn sheep in Idaho and across western North America have suffered periodic and deadly outbreaks of pneumonia. Once infected, the bacteria causing pneumonia can remain in the herds and cause disease for decades. An outbreak in the Salmon River bighorn sheep populations in the late 1980s still affects lamb survival today.

It’s long been known that contact with healthy domestic sheep can cause disease in wild sheep. The only way to prevent this from happening was to maintain separation between domestic and wild sheep, which, in many places, is easier said than done.

Recent scientific advances in understanding the underlying pathogen, Mycoplasma ovipneumoniae, is opening up opportunities for wildlife managers and ranchers to work together in new ways to protect bighorns and domestic flocks. 

Watch this video to learn how ranchers and biologists are teaming up in Challis to keep bighorn sheep healthy.  

More details and information on Movi project

Domestic sheep and goats that are Movi positive often do not have any obvious symptoms. The only way to know if sheep and goats are infected is to submit a nasal swab for laboratory testing to detect Movi DNA.

Currently, testing is free for domestic sheep and goat owners in or near areas with bighorn sheep. Idaho Fish and Game funds this project, along with support from the Idaho Wild Sheep Foundation and national Wild Sheep Foundation.

To determine if Movi is present, typically, every animal is sampled in small flocks. For larger flocks, sampling up to 20 animals that are most likely to be Movi positive will generally provide an accurate indication of flock infection status.  This includes testing young stock 6 – 12 months old and animals of all ages that have been brought in recently or have been to a fair or other location where they are likely to have been in contact with different flocks.

To find out if you are in an area near bighorn sheep where Movi testing is recommended, check out the map below showing the current distribution of bighorn sheep in Idaho. To learn more about testing for Movi, call Idaho Fish and Game at 208-334-3700 and ask for the statewide manager for bighorn sheep. 

If you want to learn more about preventing new diseases from infecting your domestic sheep and goats, the American Sheep Industry Association website has valuable recommendations for biosecurity measures that can be used to prevent diseases from being introduced and/or from spreading within a flock or to other animals. They also show the financial benefits of a healthy flock. 


Learn more about Idaho bighorn sheep by visiting this webpage.