BBC News Environment reporter, Mark Kinver, interviews WVI's Dr John Lewis regarding the press release 'Big Cats Fall Prey to Dog Disease'. John explained that a close relative of measles, Canine Distemper Virus (CDV) has been cited as contributing to the demise of the thylacine (otherwise known as the Tasmanian Tiger).

If you wind the colck back about 30 or 40 years, it was a dog disease" Dr Lewis explained. "But in the interveneing years, the virus has evolved and has changed its pattern of animals can infect to include marine mammals (such as seals) and big cats." CDV needs a reservior, like a population of domestid dogs, to remain effective as a pathogen. These conditions were present when the first case of the disease affecting wild big cats was documented. "In the mid-1990s, in the Serengeti, Africa, about 30% of the lions died from CDV, which came from dogs in surrounding villages. It has also been recognised in the Asian big cat populations," John added. Since 2000, in the Russian Far East, there have been a few cats reported as behaving strangely and coming into villages apparently not showing much fear towards people. In the past few years some of these cases have been confirmed as showing a presence of CDV infection. "There have not been too many cases at the moment, but we think there could have been more that have gone undiagnosed." John went on to explain. "While some tigers appear as if they are able to build up a reasonable immunity response, most of the animals do succumb to the disease if they are exposed to the virus. " "We do not have enough information on CDV in tigers to know what percentage go on to die. There are a lot of cases of distemper in dogs the region [Russian Far East] and tigers are partial to eating dogs. "For a tiger to take a dog on the periphery of a village is not unusal at all, so you do have the circumstances that would bring tigers into contact with CDV". While it is assumed that the cause of CDV infection in tigers was a result of coming into contact with dogs carrying the virus, Dr Lewis said that a research project was underway to look at the source in wild Amur tigers (also known as Siberian tigers). Worrying signs in Sumatra Dr Lewis goes on to talk about the behaviour change in tigers that is particularly worrying. "The apparent loss of fear of people puts them at risk because they put themselves in situations of conflict, such as playing with traffic, and do not avoid poachers." On a recent visit to Sumatra he said conversations with local wildlife vets seemed to indicate that CDV could already be present in the population of the Critically Endangered Sumatran tiger. They told him that they had seen strange behaviour indicating they did not fear people. "To me, that suggests that distemper is already beginning to have an impact on tigers in Sumatra," he warned. "But before you say that is a result of CDV, you need diagnostic testing of brain tissue. "The big threats facing tigers are habitat loss and degradation, and poaching. But I think the third biggest threat now is likely to be disease, particularly one like CDV," Dr Lewis comments. Dr Lewis is returning to Sumatra in September to bring together vets that work with the tigers. "The goal is to thrash out a very simple way of deciding what samples need to be taken from all tigers that are handled by people throughout Sumatra, in order to help with diagnostics. "We also need to thrash out what samples need to be taken from domestic dog populations, where we can send these samples for laboratory testing and we need to work out how wer are going to store and move these samples. "Once that is nailed down, then we can start work and try to design some sort of mitigation strategy, and that wont be easy," he explained.

Best get started then .......