Serengeti: Canine Distemper Virus

Small groups of endangered species may be driven to extinction by the researchers trying to keep them alive, according to the Journal Nature. The packs of wild dogs in the Serengeti and Masai Mara that died out between 1965 and 1991 were those studied by zoologists. Techniques such as trapping, darting, radio collaring and tissue sampling, caused stress and made them more susceptible to rabies.

The mysterious killer of more than 60 lions in the Serengeti national park in Tanzania this year has been identified as canine distemper virus, according to the US journal Science. It was an identical or closely related virus - a species of morbillivirus- which killed thousands of seals in the North and Baltic seas in 1988.

The virus had never been known to inflect a feline population until last year when it killed 19 lions, leopards and tigers in two Californian wild animal parks. But Max J V Appel, a virologist at Cornell University's College of Veterinary Medicine and a specialist on morbilliviruses, said there was no doubt about the culprit.

The reason for the Serengeti outbreak is still unknown, and no-one can do anything to stop it. The only hope is that those lions that are surviving the virus - and some are - will have increased immunity in the future. The virus is not the only threat to the big cat population. Ninety percent of the lions in the Kruger National Park in South Africa have FIV - the precursor of feline Aids.

A disease that gives lions convulsions has killed 85 of the animals since March in Tanzania's fabled Serengeti park and researchers fear the toll could be higher, a tourism official said. Lotal Lelamari, director-general of Tanzania's National Parks (Tanapa) said from the northern Tanzanian town of Arusha that 63 other lions had disappeared.

Lions in the Serengeti national park in Tanzania are recovering from a disease that killed up to 80 per cent of the lions in some areas last year, according to Melody Roelk-Parker, the chief veterinary officer for Tanzanian national parks. The disease, canine distemper virus, and its causes, are still being investigated but the number of deaths among lions has fallen dramatically in recent months.Tourist officials say guides operating in the Serengeti have recently reported that lion numbers are increasing. 'There are good signs that numbers will recover completely,' one said

The last wild dogs being studied in Tanzania's Serengeti National Park have died, and some researchers point their fingers at scientists studying the animals, arguing that handling--with radio collars and darts--so stressed the dogs that they succumbed to rabies infections. Wildlife biologists vigorously dispute the scientific basis of this hypothesis in a current publication and say the charges have hampered a variety of wildlife studies.

Two years ago, canine distemper virus (CDV) felled a third of the lions in Tanzania's Serengeti National Park. How did a virus historically restricted to dogs and a few other carnivores suddenly jump to cats? Now a genetic analysis indicates the Serengeti organism is a new variant. Researchers have also been able to trace environmental changes that set the stage for the mutation: human settlements along the park's border that placed CDV-infected domestic dogs cheek-by-jowl with park animals.

Canine Distemper Virus (CDV) is thought to have caused fatal epidemics among silver-backed jackals and bat-eared foxes in the Serengeti-Mara system in 1978 and among African Wild Dogs in 1991. The same disease has now been implicated in the deaths of lions in the area in 1994, according to Melody Roelke-Parker (of the Serengeti Wildlife Research Institute in Arusha, Tanzania) and colleagues (Nature, 379, p. 441).

The first signs occurred in early 1994, when six lions in the Serengeti National Park were observed with grand mal seizures, while three developed facial and forelimb twitches and others were noted to be disoriented, depressed and lacking motor co-ordination. Subsequently, a larger than usual number of lion carcasses were found.

In order to investigate the epidemic, samples were collected from a number of dead lions, as well as a number of live lions - both diseased and apparently healthy. When analysed, the samples showed the presence of CDV.

The most probable source of the virus is thought to have been the domestic dog, of which there are about 30,000 from the local villages adjoining the Park. The most probable route of transmission is believed to be by spotted hyaenas, which range among human dwellings and travel long distances in the Park and gather in large numbers at kill sites, where the environment is ideal for CDV amplification and transmission.

In all, that epidemic, which also spread north into the Masa Mara National Reserve, is thought to have reduced the lion population in the Serengeti-Mara system from around 3,000 animals to an estimated 2,000. In addition it is thought to have affected countless hyaenas, bat-eared foxes and leopards.

As a sequel to this work, Project Life Lion, working with the Tanzania Veterinary Service, has launched a dog vaccination campaign covering both distemper and rabies