Science: Orangutans sit still for heart ultrasound at zoo

The 9-year-old patient sits still, munching on popcorn and sipping grape juice while he gets an ultrasound of his heart.

It's part of a groundbreaking national project that researches heart disease in the rust-colored apes. Heart problems are the No. 1 killer of orangutans, gorillas and other apes living in captivity, and the disease threatens the work researchers have done to help increase the population of the endangered species.

Researchers have been collecting data on gorilla heart disease for a decade, but zoos are just now starting to gather that information on orangutans. In February, Zoo Atlanta was the first facility to perform an awake echocardiogram on an orangutan.

Now the zoo, through the Great Ape Heart Project, is encouraging other organizations to do awake procedures, too, and send in the data. Healthy apes can be put under anesthesia but the drugs are dangerous for those already suffering from heart problems. Awake procedures expand the amount of data researchers can collect, Murphy said.

Satu and other orangutans at the zoo were trained for awake ultrasounds and blood draws through positive reinforcement using treats and praises. It took months of training to work up to a heart ultrasound that produced a usable image.

On a recent day, Satu sat for more than half an hour while technicians performed a cardiac ultrasound on him. A laptop sitting nearby showed black and white images of his pumping heart and broadcast the thump, thump, thump of the valves opening and closing.

Afterward, zoo workers drew blood from another orangutan, Madu, while she sat quietly waiting for treats. The 28-year-old ape rested her arm in a large plastic tube built specially for blood withdrawals, which once had to be done with the animal under anesthesia, a lengthy procedure.

Training the apes to sit still long enough for any medical procedure can take up to a few months, depending on the animal. Patti Frazier, primate keeper at Zoo Atlanta, said she typically starts by teaching the orangutan to present his chest, then slowly introduces each element of the test.