How do you save a species from extinction? You can put your efforts into protecting the animals and their habitat in the wild, or you can breed them in captivity with the distant hope that one day, in a better, safer world, you might be able to release them back to nature. Even if return to the wild is never possible, at least some members of the species, although captive, will still exist on earth.

For some animals, however, captive breeding is not quite the Noah's Ark it's meant to be, as veterinarians at UC Davis are discovering for that magnificent sprinter, the African cheetah.

Although a champion athlete of the cat world, the cheetah is running way behind in the survival sweepstakes. Faring much worse than other big predators, its numbers in African have plummeted during the past two decades. The main threats to cheetahs include loss of habitat and competition from other predators. With its relatively small teeth and gracile form, cheetahs are no match against lions or hyenas wanting to steal their kills. To add injury to insult, lions kill baby cheetahs, and in some regions are the main cause of death among cubs.

Hunters also take a big toll, especially in Namibia where cheetahs share the land with farmers and ranchers. When the cats started attacking livestock during the 1980's, humans picked up their rifles and cut down the population by half.

Conservation efforts aimed at cheetahs have included captive breeding programs in South Africa and the US. Unfortunately, cheetahs have not prospered in captivity. Not only is it hard to get them to breed, but it's not easy to keep them healthy. Here's where researchers from UCD's School of Veterinary Medicine come in.

For the last ten years, Dr. Linda Munson and her colleagues have been studying why cheetahs get sick and die in captivity. The vets have identified three major disorders that are hitting the cats: chronic gastritis, and highly unusual kidney and liver diseases. While these conditions are extremely rare in other mammals, they appear to be remarkably widespread in cheetahs. For example, up to 80% of the bodies examined had some degree of the unusual kidney disease.

Munson also reports that captive cheetahs suffer from a host of chronic infections such as herpes, manifested as extensive skin ulcers. Their immune systems seem unable to mount an appropriate defense against infections.

One possible explanation is inbreeding. All cheetahs, including those in the wild, are remarkably similar to one another genetically, as if coming from the same family. Is inbreeding lowering their resistance to disease? Or is it something about captivity itself, such as diet or stress, both of which have been linked to weakened immune systems?

To answer this question, Munson took her research to Namibia in 1990 to study the health of wild cheetahs. Part of her work is to examine animals that have died. So far, post-mortems have not revealed the lethal diseases so prevalent in captivity, suggesting that inbreeding is unlikely to be the the main cause of high disease rates. More likely it's some feature of captivity, and Munson strongly suspects that stress is the culprit.

In Namibia, now the cats' main stronghold, the veterinarians are collaborating with the Cheetah Conservation Fund. Through PR and education programs, this conservation body persuades local farmers to trap cheetahs rather than kill them. The conservationists then translocate the animals either to a livestock-free area, or to a captive breeding facility. Before moving them, however, they contact the vets who take blood samples and vital statistics from the captives.

It is clear that a wild cheetah hates being trapped. Stress-related compounds in the animal's bloodstream rocket during the first few days after capture. The vets are studying how long it takes high stress levels to abate. It's possible that some animals never properly adapt, even to long-term captivity. For example, several of the physical conditions common in zoo cheetahs, such as scars in the heart, are hallmarks of chronic stress.

This veterinary research can lead to improved conditions for captive cheetahs while also providing valuable data on the relation between behavior, stress and disease in mammals. Why captivity should impact cheetahs more than other big cats, we can't yet say. What we do know from Dr. Munson's work is that hope for the cheetah does not lie in captive breeding programs, but in securing protection for them in their native habitats in Africa.

© Kelly Stewart

Dept. of Anthropology, University of California, Davis, CA 95616
e-mail: kjstewart@ucdavis.edu

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