A new and different way of thinking about Gorillias, where mounting is not a priority

Gorillas at North American zoos have been dying at alarming rates from heart disease. The San Francisco Zoo and UCSF Medical center team up to perform cardiovascular tests Wednesday on Nneka, one of the zoo's female gorillas. (Kurt Rogers / The Chronicle)

Nneka barely knew what hit her, and that's just how her doctors wanted it.

The 9-year-old, 194-pound San Francisco resident was anesthetized Wednesday morning and underwent a litany of tests by a number of respected physicians. The doctors probed and prodded Nneka for several hours, conducting X-rays of her torso, shaving parts of her chest to conduct ultrasounds of her organs, inspecting her teeth, drawing blood, and taking skin, hair and urine samples.

It would have been a mighty expensive day at the doctor's office, but for Nneka it was free, save for the embarrassingly patchy chest hair. The lowland gorilla is part of a national project that seeks to improve understanding of the giant creatures' cardiac health.

Zoos and researchers have realized in recent years that heart disease is increasingly common in captive gorillas, and they want to collect as much information on as many of the primates as they can.

On hand for the exam at the San Francisco Zoo were the zoo's head veterinarian, Jacqueline Jencek; a private veterinary cardiologist, Sam Silverman; a number of zoo hospital technicians and vets; and someone not seen in these parts very often - a cardiologist from UCSF Medical Center, Dr. Dana McGlothlin.

McGlothlin, who normally treats cooperative awake humans, signed on at the request of Jencek, who has previously received help from other UCSF anesthesiologists and radiologists. McGlothlin and her echo cardiovascular technician, Hillary Rubin, leaped at the chance.

At the end of the exam, Nneka was given a clean bill of health and McGlothlin offered to come back anytime.

The real surprise for the cardiologist?

"Gorillas' hearts are, unexpectedly, almost identical to humans' in size and shape," she said. "It would be difficult to distinguish a human heart from a gorilla's just by a cardiac ultrasound."

Gorilla heart health

The Gorilla Health Project started in 2006 and has collected data from more than 100 captive gorillas.

Q: What's the point?

A: A number of lowland gorillas in captivity have died in recent years from cardiac problems. The Association of Zoos and Aquariums wants to compile as much information as possible on healthy gorillas' hearts so they can better evaluate them later in life, begin treatment for animals that appear to be predisposed to cardiac problems, and manage and treat disease in the whole species. The information will also help the association's species survival plan, which uses complicated formulas to determine which captive endangered animals should breed.

Q: Who is participating in the study?

A: Information from gorillas at several zoos are already in the database. So far, the San Francisco Zoo has examined two of its five gorillas: 9-year-old Nneka and her mother, 28-year-old Bawang. The other three will be evaluated when they are up for their routine medical exam.

Q: What happens if a gorilla has heart disease or looks predisposed to it?

A: The same thing that would happen to a human, including preventative medication (gorillas are so similar to humans that they can be treated with the same medication) and diet changes.

Q: What's different about this exam?

A: San Francisco's gorillas and chimpanzees receive extensive medical exams every year or two. To participate in the health project, the zoo added sophisticated ultrasound equipment and a cardiologist.

Q: Do the animals cooperate?

A: Zookeepers don't even get into the cage with the 200-plus-pound creatures, let alone try to examine them up close. To conduct the exams, the gorillas must be anesthetized. If the animal is feeling cooperative, it will sidle up to the side of the cage and let vets administer a hand injection to its backside; otherwise, they are given an oral sedative so they can be injected with a tranquillizer dart. They are given anesthetic gas during the procedure to keep them unconscious.

Q: Are there risks involved?

A: Anytime a primate is put under anesthesia - humans or gorillas - there are risks, which is why the exams are so thorough and rarely done. Vets monitor the animal's temperature, heart rate and blood pressure while they are under, and keep them separated from the rest of the gorillas overnight to make sure everything is OK.

Source: San Francisco Zoo