CODY Wyo. — The Wyoming Game and Fish Department (WGFD) has documented a disease outbreak in the Devil’s Canyon bighorn sheep herd northeast of Lovell.

“Since Oct. 14, Game and Fish has documented 37 bighorn sheep mortalities in the Devil’s Canyon herd, which constitutes approximately 10 percent of the population,” said Corey Class, wildlife management coordinator for the Cody Region. “The majority of deaths have occurred in ewes and lambs.” 

On Oct. 16, Game and Fish collected biological samples including nasal and tonsil swabs and tissue from bighorn sheep carcasses at the site.  The samples were sent to the WGFD Wildlife Health Laboratory in Laramie for analysis where a pathogenic strain of the bacteria Mannheimia haemolytica was cultured. This strain type is known to cause lethal pneumonia in sheep. The source of the infection is unknown. 

Game and Fish is actively monitoring the population and any potential spread of pneumonia. Currently, 24 bighorn sheep in this herd are fitted with GPS tracking collars to monitor distribution, habitat use, seasonal movement, annual recruitment and survival rates. 

All bighorn sheep carcasses are being disposed of to decrease the spread of the disease.

“Our limited experience with this pathogen gives us some hope the outbreak will run its course quickly, with minimal mortalities,” said Hank Edwards, Wildlife Health Laboratory supervisor.

The Devil’s Canyon bighorn sheep herd (Hunt Area 12) is located in the northwest portion of the Bighorn Mountains. This population is estimated at 250-300 individuals.