If you thought human echocardiography was tough, imagine what it’s like to perform an echocardiogram on a gorilla while it’s awake:
Using wooden sticks, Niehoff and Evans touch the bars where they want Kwashi to place his hands. The gorilla complies.
"Good boy," Evans says, slipping grapes into the gorilla’s mouth.
Evans applies conductive gel to the tip of a small wand that emits high-frequency sound waves.
Then, with grapes in his left hand, Evans moves the wand in his right hand toward Kwashi’s chest, being careful not to place the instrument completely through the bars
This is where an important part of Kwashi’s training kicks in. The gorilla leans forward slightly until his chest rests against the bars. He holds that pose – and continues gobbling grapes – as the wand touches his chest.
A few feet away, Jenny Schaaf stands at a state-of-the-art cardiac ultrasound machine on loan to the zoo from Toshiba. The monitor shows the gorilla’s beating heart, which Schaaf, technical director of the echocardiography lab at Christ Hospital, captures for later analysis.
"Tilt up a little bit," she says, directing Evans on how to position the wand. "Little bit more. That’s perfect."
"Good boy!" Evans says, as Kwashi holds his pose.
A few minutes later, though, Kwashi grunts. Evans recognizes the sound as the "cough vocalization."
"That’s a warning that, ‘I don’t like what you’re doing.’ He doesn’t like his chest being touched."