Ulf Tubbesing is a pioneer veterinarian who works with wild animals in Africa. He makes "house calls" from his Namibian clinic, tending to the needs of the continent's wildest animals-and fighting to give them a sanctuary where they can recover and roam free.

"Treating and working with wildlife or, more specifically, problem animals to me is an incredible professional challenge," said the fifth-generation Namibian. "I do it for the love of it."

This week, National Geographic Ultimate Explorer correspondent Mireya Mayor joins Tubbesing as he fights to save a leopard family suffering from a deadly brain disorder. Mayor also helps capture wildebeests, giraffes, and other animals to populate a new nature preserve that's the realization of Tubbesing's long-held dream.

Dangerous House Calls

When Ulf Tubbesing makes a house call, the patient isn't always cooperative and the location is almost never inside a house. The veterinarian responds to wild animals in trouble, often because of contact with humans.

Much of Namibia's desirable land is fenced in, so many of the nation's leopards and cheetah live on farmland. They sometimes kill livestock, creating an economic problem for some landowners.

"In the past ranchers and farmers would only shoot to kill," Mayor explained. "Now some of them are calling Ulf and letting him safely move the animal off their land."

The animals often need medical attention as well. While Mayor was in Africa Tubbesing tended to a wild cheetah that had been attacked by a leopard.

"In any other circumstances the animal would have died," she reported. "It couldn't walk or eat on its own, but remarkably after Ulf's care:you wouldn't even know that it had ever been attacked."

The work is a tireless and dangerous effort, but it can make a real impact on seriously depleted animal populations like the cheetah-in which every animal counts.

"These animals don't have a lot of other options," Mayor explained, "and there are not a lot of people like Ulf:He has a real passion for these animals, in a lot of cases they would be shot and killed and if not for him and his specialized skills."

In addition to tending medical problems, Tubbesing has recently established a 25,000-acre (10,000-hectare) preserve for Namibia's wildlife. He has begun to relocate many of his patients to this area where a thriving ecosystem once existed but was hunted out. It's called the Ongos project.

Some of the new inhabitants are big cats who got into trouble with ranchers. "It's a really satisfying feeling being able to take an animal that is either doomed to life in a cage or doomed for a bullet and release it out in the wild again," he told Ultimate Explorer. "That's really exciting to know that one keeps something going, that it didn't just end with a bang."

Other animals are being relocated to the site as well, including wildebeest and giraffes.

The process of capturing and moving them to the new reserve involves an intoxicating mix of excitement and danger. Mayor helped capture and move giraffes. "That process was a lot more dangerous than I had anticipated," she reported. "It's dangerous for the animals and for the people capturing them as well." But the result is worth it: the gradual rebirth of one of the planet's great natural environments.

'Fortunate Accident' Aids Leopard Brain Disorder

Meanwhile, one of Tubbesing's fortuitous discoveries may spell great news for the leopard-and perhaps someday for humans as well. It came about because Tubbesing found himself unable to euthanize a sick leopard placed in his care. "The leopard was extremely ataxic [unable to coordinate its muscles]," Tubbesing told Mayor. "It was hardly able to walk and falling over all the time. She couldn't climb, she couldn't jump, she couldn't do anything. I just didn't have the heart to euthanize her." Instead he persuaded a local hospital to do a brain scan and discovered the animal had hydrocephalus-too much fluid in her head. The genetic disorder causes brain and spinal cord damage, and often proves fatal.

Tubbesing gave the ailing leopard, named Umqua, a vitamin supplement that is normally used to treat human liver ailments. Within mere days she showed remarkable, dramatic improvement. "Some of the better things in life happen by accident," Tubbesing mused. "This is one of those things."

Umqua made a near full recovery, and the wild vet is now prescribing the same treatment to afflicted cubs from the same family.

"We don't know why it's working," he said. "You can't interpret it in scientific terms, but emotionally there is something substantial to this treatment and it is worth pursuing."

Mayor noted that the same affliction affects humans and that to date it has no cure. "The treatment seems to be working so well that it could eventually be worth pursuing some kind of study for humans," she said.

So someday, the wild vet's fortunate discovery could benefit people. For now, it's enough that it is benefiting just a few special animals.