Investigating Pseudorabies Virus as a Mortality Factor for California Mountain Lions

Abstract

Wild pigs in North America carry multiple pathogens capable of causing diseases in wildlife, people, and domestic animals. Wild pigs are the reservoir host of pseudorabies virus (PrV) which is a fatal infection in wild carnivores. We previously conducted surveillance for PrV in wild pigs from Kern County, California where the distribution of wild pigs overlaps with native mountain lion. We found that 100% of wild pigs were exposed to PrV, and 6% were shedding the virus. Black bears and pumas have been observed preying on wild pigs in the region suggesting that they are vulnerable to exposure to PrV from pigs. We conducted retrospective, post-mortem surveillance for PrV on 16 pumas from five counties in south central California. None of the pumas tested positive for PrV. In Florida, PrV is attributed to one-third of the deaths in Florida panthers. Wild pigs are a large portion of the diet of panthers in Florida, but studies in California suggest pigs may not be utilized as frequently. This difference in diet could account for the lack of evidence that PrV causes measurable mortality in California pumas. Nonetheless, in management areas with carnivores, wild pig management should be carefully considered.