Tuberculosis Imperils Lions in Kruger Park

The spread of tuberculosis among the lions in South Africa's Kruger National Park is raising fears that the entire lion population may be at risk. TB has occurred primarily in buffalo in the southern sector of the park, where 1,300 of Kruger's estimated 2,000 lions live. How many lions (and members of other species) have been infected is not clear, but in skin tests performed recently on about 30 thin, unhealthy lions, 90 percent tested positive for TB.

Tuberculosis is a debilitating bacterial disease that usually affects the lungs and can occur in most warm-blooded animals. Some infected animals may live for years with few or no symptoms; others weaken quickly, become emaciated and die within weeks or months.

One of Africa's largest national parks, Kruger is 55 miles wide and 250 miles long. TB is believed to have entered the park via infected cattle in the early 1960s, before domestic livestock were fenced out. In 1990 an infected cape buffalo--one of thousands in the park--was found; since then, TB has slowly spread among most buffalo in the southern sector.

"Buffalo, as herding animals, spread TB among themselves by coughing in each other's faces," Dr. Michael Woodford, chairman of the Veterinary Specialist Group of the World Conservation Union's Species Survival Commission, told the Wildlife News. "Lions are thought to rarely spread the disease to other lions. But they often lie around and feed in groups, so that several may become infected by eating a single sick buffalo."

With no feasible cure and no preventive vaccine yet available, there are few agreeable options for eliminating the disease in wildlife areas. The usual method in domestic animals is to test the animals and slaughter the infected ones. For wildlife, one option is to separate the sick from the healthy by fencing off, in the case of Kruger, the infected southern region and erecting a second fence several miles south of the first. Buffalo in the fenced zone would be killed to "cleanse" the area. (Uninfected buffalo herds from the north would later repopulate the area.) The zone would be moved further south, gradually enlarging the uninfected area, until entire park was cleared of tubercular infection.

Fencing actually won't be an option, Woodford said, until experiments determine how long it takes a zone to become completely germ-free after the buffalo are eradicated.

The last, and most draconian, option would be to slaughter all the buffalo in Kruger.

"Under relatively undisturbed conditions, wildlife disease may be present but is only one cause of mortality among many," said Mark R. Stanley Price, director of AWF's African operations. "In much of Africa, however, where livestock are now more numerous and veterinary controls are less rigorous, disease outbreaks are far more serious."