BOSTON -- Okpara, a western lowland gorilla, was reported to be doing well Tuesday after being put under anesthesia for a physical exam.

Photos: Gorilla Gets Physical Exam

Anesthesia, which presents risk to gorillas, was required so that Zoo New England veterinarians could fully exam him.

The examination included a general physical, bloodwork and a cardiac exam.

“Okie is 15 years old and he is at the age where we start to get concerned about cardiac disease. We had never done an echocardiogram on him before and this is preventative care,” said Dr. Hayley Weston Murphy, Zoo New England director of veterinary services.

Cardiac disease is the leading cause of death in male captive gorillas, according to Murphy, who is leading a national study, the Gorilla Health Project, which aims to find ways to prevent the disease.

Blood work results, which will include information on Okie’s cholesterol levels and cardiac biomarkers, are expected within a week.

“Nobody has ever tried to look at the risk factors for developing cardiac disease in gorillas,” said Murphy.

Cardiac biomarkers are protein molecules released into the bloodstream from heart muscle damaged by a blocked artery, according to the zoo.

While Okie’s examination was considered routine, anesthesia presented concerns for the staff.

“Any animal immobilization involving general anesthesia always carries some risk,” said Murphy.

Kubandu, a western lowland gorilla, died of complications from anesthesia during an annual physical exam at the zoo in 1997.

Earlier this month, zoo veterinarians anesthetized another gorilla, Gigi, in order to perform a colonoscopy. The gorilla had been suffering from digestive problems. The colonoscopy results were normal.