The Far Eastern or Amur leopard is already among the rarest of the world’s big cats, but new research reveals that it faces yet another threat: infection with canine distemper virus (CDV). A new study published last month in the Journal of Wildlife Diseases: Canine Distemper Virus in a Wild Far Eastern Leopard (Panthera pardus orientalis), describes the first documented case of CDV in this rare big cat.
The case involved a two-year-old female leopard that was found along a road that crosses the Land of the Leopard National Park, in the Russian territory of Primorskii Krai.
“The leopard was extremely sick when she was brought in, and had a severe neurological disease,” said Ekaterina Blidchenko, veterinarian with the National Park and the TRNGO Animal Rehabilitation Center. “Despite hand-feeding and veterinary attention, her condition worsened, and a decision was made to euthanize her for humane reasons.”
Although CDV is well known in domestic dogs, it also infects a wide range of carnivore species, including big cats. In 1994, a CDV outbreak in Tanzania killed over 1,000 lions in the Serengeti National Park.
Nadezhda Sulikhan, a scientific staff member of Land of the Leopard National Park, stated: “The leopard virus was genetically similar to infections we’ve diagnosed in wild Amur tigers. But we think these infections have spilled over from a disease reservoir among domestic dogs, or common wild carnivores like badgers and foxes.”
Unlike the outbreak situation in a pride species such as lions, outbreaks of CDV are likely to spread more slowly among solitary cats like leopards and tigers. However, even infrequent transmission can have profound consequences for the species concerned. Research has estimated that extinction of small populations of tigers is 65 percent more likely when they’re exposed to CDV.
Globally, carnivore populations are being pushed into smaller and more fragmented islands of habitat. If these trends continue, infectious diseases are likely to become a greater threat to carnivore survival in the future.
The combined pressures of habitat degradation, hunting and prey depletion have already marginalized this subspecies to a single population of approximately 80 individuals along the border of the Russian Far East and neighboring northeast China. Conservationists now need to understand the severity of this new-found threat, and also where it is coming from, as this information is critical for developing measures that counter the disease’s impact.
Dr. Sulikhan advises, “Until we know where the virus is coming from, it is impossible to target vaccinations or other interventions to prevent infections in leopards. We are now working to unlock this riddle, and understand the importance of domestic dogs versus wild sources of the virus.”
For now, the most effective way to combat this new disease threat is through traditional carnivore conservation approaches; reducing hunting and protecting habitat.