Septicemic listeriosis in wild hares from Saskatchewan, Canada

The bacterium Listeria monocytogenes causes disease in a wide variety of mammals including rabbits and hares. We describe naturally acquired metritis and septicemic listeriosis in wild female hares from Saskatchewan, Canada. Between April 2012 and July 2013, two white-tailed jackrabbits (Lepus townsendii) and a snowshoe hare (Lepus americanus) were presented to the Veterinary Medical Centre at the Western College of Veterinary Medicine, Saskatoon, Saskatchewan, Canada with nonspecific neurologic signs. The hares were euthanized and autopsied. Necrotizing fibrinosuppurative metritis was present in all. Additional findings in individual hares included fetal maceration, multifocal necrotizing myocarditis, multifocal hepatic necrosis, and nonsuppurative encephalitis. Listeria monocytogenes was cultured from multiple tissues in each hare. Although listeriosis in pregnant domestic rabbits has been studied, this is the first detailed description in wild North American hares. The epidemiology of listeriosis, including prevalence and the role of environmental sources and coprophagy in transmission among hares, requires further investigation.