The Eurasian strain of highly pathogenic avian influenza was detected in two mountain lions in Mono County in December 2022 and January 2023, according to a press release sent out by the California Department of Fish and Wildlife on Tuesday.
While additional disease testing is being conducted to rule out the possibility of co-infections, avian influenza is suspected to be the cause of the death for both mountain lions, according to wildlife experts with the California Department of Fish and Wildlife.
This is the second species of wild mammal known to have contracted avian influenza in California since the virus was reported in wild birds in July 2022. In January, the virus was detected in a bobcat found in Butte County.
The new findings also mark the first detection of avian influenza in Mono County. To date, the virus has been found in 45 counties statewide.
“The Eurasian lineage of avian influenza is primarily a disease impacting birds but is occasionally being detected in wild mammals. We don’t expect this to have a population-level impact for California’s mountain lions or other mammalian carnivores, but it is a disease we will continue to monitor,” Dr. Jaime Rudd said in a press release, a pesticide and disease investigations specialist for the California Department of Fish and Wildlife.
Remains of the two mountain lions, who were related (mother and daughter), were collected from Mono Lake in Mono County on December 23 and January 14. Samples were submitted to the California Animal Health and Food Safety Laboratory in Davis for preliminary testing. Last week, the U.S. Department of Agriculture’s National Veterinary Services Laboratories confirmed the detection of avian influenza.
Both mountain lions were wearing GPS collars as part of a California Department of Fish and Wildlife population study. The mortality notification sent from the collar helped biologists track the deceased animals and allowed for their remains to be collected in a timely manner to perform necropsies and determine cause of death.
According to the press release, infection of wild mammals with avian influenza viruses appears to be relatively rare. Detections in mountain lions have occurred in five other states.
The strain of avian influenza currently circulating in the U.S. and Canada has caused illness and death in a higher diversity of wild bird species than during previous avian influenza outbreaks, affecting raptors and avian scavengers such as turkey vultures and ravens. Mammalian and avian predators and scavengers may be exposed to avian influenza viruses when feeding on infected birds.
Currently, the CDC considers the transmission risk of avian influenza to people to be low, but recommends taking basic protective measures (i.e., wearing gloves and face masks and handwashing) if contact with wildlife cannot be avoided. The California Department of Fish and Wildlife does not recommend people handle or house sick wildlife.
Please report sick or dead poultry and pet birds to the CDFA hotline at (866) 922-2473 or use this link.
For non-urgent questions concerning wildlife, contact your local CDFW Regional Office or your local animal control service.