Slideshow: Tackling Dog Fever in Serengeti Lions

No dog news is good news, at least as far as a cat is concerned.

A strategy currently used to control the spread of the infectious canine distemper virus (CDV) by vaccinating domestic dogs that likely first transmitted it to Serengeti lions (Panthera leo) may not be very effective for the big cats.

A new study released yesterday in the Proceedings of the National Academy of Sciences shows that while vaccination may control the disease in domestic dogs themselves, it may be necessary to take other measures including vaccination of lions (Panthera leo) to prevent further spread of this devastating disease among the cats and other vulnerable wildlife.

“[CDV] often kills the animals, so much that in 1994 approximately 1,000 lions in the Serengeti were killed,” said Mafalda Viana, a mathematical biologist at the University of Glasgow and the lead author of the study.

In 1996, wildlife managers and others began implementing programs to vaccinate domestic dogs in villages surrounding the Serengeti National Park in Tanzania, hoping that would stop further transmission of the disease to the park’s lion population.

A lion with myoclonus, involuntary muscle spasms, possibly associated with previous infection with canine distemper virus during a 1994 outbreak.
Image Credit: Serengeti Carnivore Disease Project People line up with their dogs during a CDV vaccination campaign.
Image Credit: Serengeti Carnivore Disease Project A young child waits to have his puppy vaccinated against CDV during a vaccination campaign.
Image Credit: Serengeti Carnivore Disease Project Veterinarian Magai T. Kaare samples a dog during a CDV vaccination campaign.
Image Credit: Serengeti Carnivore Disease Project A young child holds a puppy for vaccination during a CDV vaccination campaign.
Image Credit: Image courtesy of the Serengeti Carnivore Disease Project

“Until now no one had looked at whether this vaccination program was actually working on the dogs or the lions,” said Viana. Her study found that while domestic dog vaccination helped dogs, it wasn’t enough to prevent lion infection as other species including jackals, hyenas, mongooses, and endangered African wild dogs (Lycaon pictus), also infected with the disease, could be transmitting it to lions. In fact, African wild dogs have been badly hit by CDV with a pack of dogs near the Serengeti recently suffering more than a 90 percent mortality rate.

“We could start thinking about vaccinating endangered species directly,” Viana said about potential management strategies to stop the spread of CDV. However, since the vaccines currently used were developed with dogs in mind, their effectiveness with lions or other species is unknown. And even if the vaccinations used for domestic dogs may be safely translated to African wild dogs, “it’s not easy to go and catch a wild dog, and there are certain ethical aspects that should be considered.”

Some would also argue that it’s best not to interfere at all in cases involving wild animals. But Viana feels the discussion needs to happen, regardless of what is decided. Siberian tigers (Panthera tigris altaica) have been hit hard in the past few years due to CDV-related causes and scientists are discussing intervention with that species as well.

“Manipulating wildlife is never an easy decision,” Viana said.