Major new research has been under way in Russia to help discover how the country’s Amur tigers are contracting canine distemper virus (CDV) highlighted by UK charity Wildlife Vets International as a potential killer of tigers in many countries.

In the Russian Far East CDV has been definitively diagnosed in two wild tigers with neurological symptoms and unnatural behaviour. Other clinically similar cases suspicious of CDV in wild Amur tigers have not been confirmed by laboratory testing, but a recent scientific paper (Seimon et al, 2013) confirms CDV as an emerging disease in the Amur tiger, directly or indirectly responsible for the deaths of approximately 1% of the wild population. The paper concludes “Our report illustrates the importance of long-term wildlife monitoring and health surveillance in identifying emerging threats in endangered species. Identifying animal reservoirs for CDV and identifying the CDV strains that are transmissible to and among wildlife species, including Amur tigers and sympatric critically endangered Amur leopards (Panthera pardus orientalis), is essential for guiding conservation and mitigation efforts.” So where has the disease come from – wildlife or pets? Is tiger CDV related to dog CDV at all? Russian vet Misha Goncharuk (ZSL) was trained in wildlife medicine by WVI’s Dr John Lewis. In a recent blog he describes being part of a team of Amur Leopard and Tiger Alliance (ALTA) partners working together to investigate the where the reservoir for this disease may be. The team was spearheaded by Martin Gilbert, an epidemiologist from Glasgow University and field vet for Wildlife Conservation Society Russia. Other partners include; the Institute of Biology and Soil (IBS) of the Russian Academy of Sciences; Primorskaya State Agricultural Academy, Ussurisk; the Bureau of Forensic Examinations, Ussurisk; Terney County Veterinary Services, Russia and the Zoological society of London (ZSL), UK. Seimon et al (2013) noted that domestic dogs and wildlife such as raccoon dog were the most likely disease reservoir. There is little evidence to suggest transmission between tigers and tigers are known to encounter and kill domestic dogs. The first phase of investigation involved trapping and testing small wild carnivores in tiger and leopard habitat. Misha joined the following phase, focusing on domestic pets around the “Land of the Leopard”, a recently created large national park. A team of 10 vets and vet students spent four weeks interviewing 2000 pet owners and taking blood samples and nasal swabs from 200 dogs and cats, working through large towns and into smaller villages where every house was visited. They talked to current pet owners about animals that they had previously owned and, critically, about diseases they had suffered from, including ones with symptoms similar to canine distemper. As Misha concludes in his blog, the results from this work will allow a greater understanding of significant disease threats to the Amur tiger and Amur leopard. Having been integral to ensuring wildlife health surveillance is central to successful conservation of the Amur leopard and tiger, WVI vet John Lewis is delighted with how things are progressing in Russia. John has recently returned from Indonesia following a meeting to initiate a tiger disease surveillance programme covering the whole of Sumatra. WVI also hopes to be back in Bangladesh in 2014 to facilitate a similar programme in that country.

Amur tiger. Photocredit Dale Miquelle

References

Seimon TA et al. (2013) Canine Distemper Virus: an Emerging Disease in Wild Endangered Amur Tigers mBio4(4):e00410-13. Doi:10.1128/mBio.00410-13

Misha Goncharuk’s blog