KTKA

At 11-years-old, May, a Fennec fox, is losing her hair. Virginia, 18, a grey seal, is going blind from glaucoma. Marta, 18, a black leopard, has severe arthritis.

"Animals are very similar to humans. And, as we age the animals face the same conditions that humans do," Chicago Lincoln Park Zoo veterinarians Dr. Robyn Barbiers said.

Animals often live much longer in captivity than they do in the wild. So, zoos are increasingly dealing with geriatric animals.

The staff at the Chicago Lincoln Park Zoo puts animal Rogaine into May's diet.

Jojo, 28, an aging gorilla, takes a gentle aerobics class to stay fit. In captivity Jojo could live into his 50s.

"I notice he sometimes has to go into the corner and catch his breath," primate zoo keeper Dominic Calderisis said.

Of course, for humans and animals alike, one of the first things to go is eyesight. That is certainly the case for seals. And, it makes them more reliant than ever on their trainers for help.

Zoo animals may live longer because their lives are easier. But, that presents new challenges.

"The lion out in the wild would be chasing down its prey, so it gets a lot of exercise. Here he just has to go inside and get his food," Barbiers said.

"The stimulation that animals get in the wild, the struggle for day to day existence, keeps them fit, keeps them strong. In a zoo setting,you don't have those same pressures," Wayne Pacella, CEO and President of the Humane Society of the United States said.

An elephant in the wild will roam 30 or 40 miles in a day. That is something no zoo can recreate. So, the Humane Society of the United States argues some animals such as elephants and polar bears should never be in zoos.

While zoos cannot recreate the wild, they can provide excellent medical care .

"We care for our animals from birth until death," Barbiers said.

Tala is a red wolf, one of the most endangered species in the U.S. She is under anesthesia for her annual checkup. She will be tested for liver, heart and cardiovascular disease. She will even have her teeth cleaned. Tala will get this kind of care throughout her entire life; which is likely to be very long.