Wildlife health is linked to human and domestic animal health, which is why our team routinely assesses the health of mountain lions and bobcats that are captured. All animals are given a complete physical examination while under chemical immobilization, including blood, DNA and fecal sampling.
Our studies shows that mountain lions in southern California are exposed to a variety of infectious diseases, including Feline Leukemia Virus, originating in domestic cats (Petch et al. 2022). This is concerning in genetically restricted mountain lion populations, where proximity of mountain lions to domestic cats makes virus introduction possible, and where the outcomes of this could be fatal for the mountain lion.
Mountain lion exposure to anticoagulant rodenticides remains a concern in all of our study areas in California. The majority of the deceased southern California mountain lions that we have recovered and analyzed for these substances have tested positive for one or more of these compounds. In some mountain lions in our study area the levels were consistent with the amounts found in other mountain lions that have died as a consequence of the compounds’ direct toxic effects (Riley et al. 2007, Rudd et al. 2018). We have also begun detecting other rodenticides that can cause toxicity in mountain lions, such as bromethalin. This emphasizes that although rodents are not a primary prey item of mountain lions, that other animals such as coyotes that eat rodents are eaten by mountain lions and provide a pathway for rodenticides to impact mountain lions secondarily.