“For some reason there is a tendency to assume that one wild animal is a suitable model for another related species, whereas similar evidence would not be acceptable in human or veterinary medicine. For example, Shulaw etal. (1986) developed a serologic test to detect antibodies to Mycobacterium aviumssp. paratuberculosisin white-tailed deer, but determined the validity of the test “in deer” by using samples from infected sika and fallow deer. It is doubtful that a test developed to detect disease in humans would be accepted for use in public health circles, if its validity had been established by using squirrel monkeys and baboons!”