Mizani, a 12-year-old western lowland gorilla at the San Diego Zoo Safari Park, is back with his troop after undergoing what the park calls the world's first mastoidectomy on a gorilla. To save him from a deep-seated ear and skull infection that imaging showed had spread into bone, veterinarians teamed up with UC San Diego Health surgeons and adapted human skull-base techniques for their 400‑plus‑pound patient. The operation, performed at the park’s Harter Veterinary Medical Center, ran about five hours from anesthesia induction through recovery. By a recheck in early June, caregivers say Mizani was showing clear improvement and had returned to his normal diet and activity.
How the infection was found
According to a press release from San Diego Zoo Wildlife Alliance, wildlife care specialists first grew concerned in March 2026, when they noticed Mizani was reluctant to open his mouth, had a decreased appetite and was frequently holding his head. A CT scan followed and confirmed sinusitis and mastoiditis. Based on how advanced the disease appeared, park staff believe the infection likely began before Mizani arrived at the Safari Park in November 2024.
The team and the technique
To tackle the rare case, UC San Diego Health surgeons joined Safari Park veterinarians in an intensive planning effort led by otologist Jeffrey P. Harris, MD, PhD, whose UC San Diego Health profile lists mastoidectomy and skull-base surgery among his specialties. Dr. Harris said, per the San Diego Zoo Wildlife Alliance, “Our surgical team regularly performs complex mastoid and skull base procedures but applying that expertise to a critically ill gorilla required meticulous planning.” The group also included Kris Suresh, MD, a resident fellow at UC San Diego Health, along with wildlife care specialists who carefully mapped anatomical differences between humans and gorillas before heading into surgery.
The operation and the hospital
Per PR Newswire, the procedure lasted approximately five hours from anesthesia induction through recovery and involved more than 20 veterinarians, physicians, registered veterinary technicians, wildlife care specialists and support staff. The team operated at the Paul Harter Veterinary Medical Center, a facility outfitted with a CT table large enough for a silverback gorilla and an overhead hoist that can safely move animals weighing up to 2,000 pounds. Those features were crucial for imaging and operating on such a large and vulnerable patient.
Why the case matters
“This case was particularly unique because this disease is rarely seen in gorillas, making it a valuable learning opportunity for everyone involved,” senior veterinarian Ryan Sadler said, according to PR Newswire. Park officials say Mizani’s recovery, and the collaboration between zoo veterinarians and human surgeons, underscores how cross-disciplinary techniques can be adapted for other great apes in need of advanced care. Mizani will remain under close observation and is scheduled for another recheck in one year unless new clinical signs appear.
