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Taming a Reluctant Patient
Heart Disease Is Killing Gorillas at North American Zoos, But Testing the Mighty Apes for Signs of Illness Is a Touchy Subject

By Michael E. Ruane
Washington Post Staff Writer
Friday, March 14, 2008

"Handsome" has been feisty this morning. The young, 170-pound gorilla has been galloping around his National Zoo enclosure, rattling the cage and leaping on the mesh like Spider-Man, until just now.

Although the animal's real name is Kwame, veterinarian Suzan Murray gently calls him Handsome as she strokes the arm he has stuck into the plastic sleeve protruding from his cage.

It is a tense and potentially dangerous moment. As she soothes him during a recent training session, Murray presses a capped needle for drawing blood against Kwame's arm through an oval hole in the top of the sleeve. Suddenly, the gorilla shoots his gigantic hand through the hole. Murray recoils. Kwame dashes away.

And there is a pause in the national gorilla heart disease project.

Across North America, home to 368 western lowland gorillas in 51 zoos and one private preserve, the animals are dying of heart disease at an alarming rate. Forty-one percent of deaths among captive adult gorillas result from heart disease, experts say, and 75 percent of cardiac-related deaths occur in males.

This week, the Detroit Zoo announced the death of a 34-year-old male gorilla that had been suffering from heart problems for years.

Two years ago, Washington's National Zoo lost two gorillas to heart disease in two days. The first, Kuja, died on the operating table while surgeons were preparing to implant a device like a pacemaker. The other gorilla, Mopie, died as keepers were introducing him as the leader of Kuja's family. Cavorting around in his new role, Mopie collapsed and died.

In addition to Kwame, the zoo has two other male gorillas and three females. All are relatively young and seem to be in good health, the zoo says.

A team of scientists from across the country, led by a group that calls itself "the Gorilla Girls," is focused on trying to find out why the animals contract and die of heart disease. Is it diet? Disease? Old age? Environment? Something else?

Their first challenge is proper diagnostic testing.

But gorillas, which weigh as much as 500 pounds, do not readily hop onto an examining table to have blood drawn or their blood pressure tested. Although usually docile, they are powerful and unpredictable and can easily injure a keeper. So to be thoroughly examined, a gorilla must be rendered unconscious with anesthesia.

That can be a hazardous procedure, which experts prefer to do only periodically, said Murray, the National Zoo's head veterinarian and a Gorilla Girl.

Also, she said, anesthesia alters the animal's heart rate and blood pressure, causing abnormal readings.

How, the experts wondered, to get an awake gorilla to submit to a blood test?

Murray said she realized that if any zoo could figure it out, the National Zoo could. The keys were the zoo's giant pandas.

"The keepers that take care of the gorillas . . . are also the keepers that train the pandas," she said. "The pandas are trained for awake blood draws, awake blood pressure [tests], awake radiographs of their chests. It's amazing."

The prospect of training a gorilla to do the same thing, although daunting, was tantalizing, because the zoo has a blood test that could warn of heart trouble.

Gorilla heart disease is different from human heart disease, Murray said. Rather than suffer blocked coronary arteries and heart attacks as humans do, gorillas develop a hardening of the heart muscle, a condition called fibrosing cardiomyopathy. There are few symptoms.

Gorillas in captivity can live into their 50s, longer than in the wild, where they are more exposed to disease and human depredation. And in captivity, if their disease is detected in time, they can be treated with the same techniques used to treat humans.

Last month, two gorillas at Cleveland's Metroparks Zoo were placed on human heart drugs, said Pam Dennis, a veterinary epidemiologist at the facility and a Gorilla Girl. A gorilla at the zoo in Knoxville, Tenn., has been on human heart drugs for three years. And four years ago, a gorilla at the Birmingham, Ala., zoo had a pacemaker-like device implanted.

As in many health matters, human and animal, early diagnosis is crucial.

So twice a week for the past year or so, the National Zoo has been training Kwame to submit to a blood test.

It has not been easy. He is only 8, essentially a gorilla teenager.

The plastic sleeve was designed to be attached to the cage so Kwame can place his arm in it, and there is a hole at the top so veterinarians can insert a needle.

Keepers get him to insert his arm by feeding him grapes, but care has to be used, because he can reach through the hole.

One morning last week during a training session, Teresa Anderson and Becky Malinsky coaxed Kwame into a holding area, where, in exchange for grapes, he stuck his arm through the sleeve.

Murray sat next to the sleeve with medical instruments. Anderson dropped grapes into Kwame's mouth. Malinsky watched for any sign of trouble.

The team has yet to draw blood from Kwame. Murray is still getting him used to the procedure, to the sight and feel of the instruments. During the session, she showed him the tiny, capped needle.

"Touching," she said, as she touched Kwame's arm. "Nice job. Verrry good." The session was brief. It was important that the gorilla enjoy the experience and eventually get bored with the needle.

Overall, he did well, and the keepers rewarded him with honey.

As for his unexpected arm thrust, "We try not to react to it," Anderson said. "Hopefully, he'll get over it."

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