Rare plague case confirmed in Idaho mule deer by WSU pathologists

On June 9, a member of the public reported a mule deer in Custer County, Idaho, that was blind and emaciated. The following day, an officer from the Idaho Department of Fish and Game located the deer and euthanized it. Subsequent testing of tissue samples and the deer's eyes at the Washington Animal Disease Diagnostic Laboratory (WADDL) confirmed the presence of plague, a disease caused by the bacterium Yersinia pestis, which is naturally occurring in the western United States. This case marks the first documented instance of plague in a deer in Idaho, adding to the five previous cases recorded in other states. Plague is known to cause ocular plague in deer, leading to blindness and other severe symptoms. The disease primarily circulates among wild rodents and can pose significant health risks to humans, including severe illness and potential death if not treated promptly with antibiotics. As a regulated pathogen, the confirmation of this case necessitated reporting to the Centers for Disease Control and Prevention (CDC). Wildlife officials have advised hunters and the public to avoid contact with any animals displaying abnormal behavior or blindness. They recommend documenting the location and species of such animals and reporting these findings to state wildlife agencies. This incident underscores the importance of monitoring wildlife health and the potential risks posed by zoonotic diseases. The testing process involved the destruction of all samples after analysis to ensure safety. This case serves as a reminder of the ongoing presence of plague in wildlife and the need for vigilance among those who interact with or observe wild animals.