Chattanooga Zoo chimpanzees advancing understanding of heart issues

Chattanooga Zoo has lost two chimpanzees to heart disease, and veterinarian Tony Ashley is working with Memorial Health System’s Chattanooga Heart Institute to learn more about the issue. The zoo’s chimpanzees undergo an echocardiogram annually as part of their physical exam, and the work is part of the Zoo Atlanta-based Great Ape Heart Project. Cardiologist Bill Warren says he is seeing striking similarities in disease between humans and apes. The Washington Times/The Associated Press

CHATTANOOGA, Tenn. (AP) – The camels paid no mind as the bulky white computer cart rumbled past their pen on a recent afternoon.

And the African spur-thighed tortoises barely lifted their wrinkly heads to acknowledge the ultrasound machine as it rolled into a bamboo thicket and entered the Gombe Forest.

But in a cavernlike back room at the Chattanooga Zoo, Goliath knew something was afoot in his domain.

And he didn’t like it one bit.

As a sedative-laced dart hit the 38-year-old chimpanzee’s skin, his powerful shrieks echoed through the building, until his eyes slowly closed and his head slumped to his chest.

Finally, when the anesthetic had lulled Goliath to sleep – his fingers gently curled at his side – four zoo staff members wrapped him in a blanket and hoisted his 154-pound frame over to a folding table covered in a flowered sheet.

There Eric Smith, an echocardiographer with Memorial Health System, leaned over the reluctant patient and rubbed some ultrasound gel on the chimp’s hairy barrel chest, as cardiologist Dr. Bill Warren readied the ultrasound machine.

The slice of screen suddenly lit up with the steady throb of muscle. A gushing sound filled the room – sound waves tracking the velocity of blood flow. And as the ape’s chest rose and fell with his breath, colorful lines spiked and fell across the screen:

Goliath’s heartbeat.

“His heart has the same measurements and valve structures as the human heart,” explained Warren. “If you had shown us pictures without telling us that it was a chimpanzee, we wouldn’t have known the difference.”

That’s why zoo veterinarian Dr. Tony Ashley first reached out to Memorial’s Chattanooga Heart Institute three years ago.

Hank – Chattanooga’s famous chimpanzee and the zoo’s former mascot – had recently died of heart disease, without showing any clear symptoms. Ashley wanted to introduce more preventive measures with the rest of the zoo’s chimps.

Heart disease is the No. 1 cause of death among chimpanzees, gorillas and orangutans living in captivity. Three months ago another Chattanooga Zoo chimp, Annie, also died of heart complications. She was 28 years old.

Ashley’s skill with the animals doesn’t extend to the specificity of cardiology. But he knew an echocardiogram used on humans would be just as revealing for chimps. Such tests have become more common at zoos.

“I called the hospital and said, ‘I’d like to conduct an echocardiogram on a chimpanzee,’” Ashley remembers. “I got passed around until I was talking to the hospital’s CEO. I don’t think they really knew what to do with that statement.”

Goliath’s echo is now the third test performed by Warren and Smith at the Chattanooga Zoo, as part of a partnership between the two organizations that Warren calls “a public service.”

While the two have performed hundreds of such tests on humans, it hasn’t lessened the strangeness of working on the powerful apes.

“The first time, the chimp actually growled while we were doing the test,” said Warren. “Maybe it was my stomach. Either way, it was a little unnerving.”

The Chattanooga chimps’ initial echocardiograms have been submitted to a database with the Great Ape Heart Project based at Zoo Atlanta. The project is a national effort to investigate cardiovascular disease in great apes in hopes of curbing the number of such deaths.

So far, reports have shown remarkable similarities in how heart disease afflicts both apes and humans, Warren said.

Now the echocardiogram has become part of the chimps’ annual physical exams. As Warren and Smith examined Goliath’s heart Wednesday, Ashley and the other technicians worked quickly to measure Goliath’s height, collect his blood and conduct a TB test. Another worker swiftly clipped his fingernails and toenails.

Goliath’s heart looked good, said Warren, and the group finished up just as Goliath began to stir. Quickly, the zoo workers detached him from the mechanism and gently moved him to a bed of hay.

And before the chimp awoke from his slumber, the ultrasound machine had been whisked out of the ape den, past the turtles and the camels, and back to more hospitable territory.