First reported gorilla mastoidectomy performed at San Diego Safari Park

San Diego Zoo Safari Park and UC San Diego Health say they’ve completed the first reported mastoidectomy on a gorilla, a milestone case involving Mizani, a 12-year-old male western lowland gorilla treated for an infection that had spread into the mastoid bone behind his ear. The organizations said the surgery was performed after CT imaging confirmed both mastoiditis and sinusitis, and after clinicians determined that medical management alone would not be enough. Mizani is now back with his troop and had no signs of complications at an early June 2026 recheck, according to the zoo alliance. (sandiegozoowildlifealliance.org)

The immediate clinical story began in March 2026, when wildlife care specialists noticed changes in Mizani’s behavior: he was reluctant to open his mouth fully, was eating less, and appeared to have head pain. Imaging at the Safari Park’s Harter Veterinary Medical Center identified disease in the sinuses and mastoid region. San Diego Zoo Wildlife Alliance said the extent of disease suggested the condition may have predated Mizani’s arrival at the park in November 2024. (sandiegozoowildlifealliance.org)

The operation brought together more than 20 veterinarians, physicians, registered veterinary technicians, wildlife care specialists, and support staff from the zoo and UC San Diego Health. According to the zoo alliance, the team made an incision along the left side of the head, drained the infected area, removed infected mastoid bone and tissue, and then closed the site. The full procedure, from anesthesia induction through recovery, lasted about five hours. UC San Diego otolaryngologist-head and neck surgeon Jeffrey Harris, MD, PhD, and resident fellow Krish Suresh, MD, were identified as key surgical contributors. (sandiegozoowildlifealliance.org)

What makes the case notable is not just the surgery itself, but the apparent lack of prior published precedent. San Diego Zoo Wildlife Alliance said a search of the scientific literature found no earlier record of this specific procedure in a gorilla. That claim appears plausible based on available indexing: searches surface prior reports of gorilla sinus surgery, but not mastoidectomy. One published example is a 2018 case report in International Forum of Allergy & Rhinology describing life-saving endoscopic sinus surgery in a critically ill western lowland gorilla, performed through a similar human-veterinary collaboration. (sandiegozoowildlifealliance.org)

The organizations framed the case as another extension of a long-running model in zoo medicine, where subspecialists from human health systems are brought in for anatomically comparable, technically demanding procedures. UC San Diego clinicians previously assisted Safari Park teams with cataract surgery on a 3-year-old gorilla in 2020, and the broader literature includes other collaborative great ape ENT interventions. In the current case, Harris said the team relied on CT-based planning and adapted human skull base and ear surgery techniques to account for both the anatomical overlap and the important differences between humans and gorillas. Ryan Sadler, DVM, senior veterinarian at the Safari Park, described the disease as rarely seen in gorillas and called the case a learning opportunity for everyone involved. (sandiegozoowildlifealliance.org)

Why it matters: For veterinary professionals, this case highlights how referral-level diagnostics and interprofessional planning can change what is treatable in zoological practice. Mastoid disease in a great ape presents obvious constraints: limited published guidance, complex anesthesia and recovery needs, high-value patients in managed conservation populations, and the need to adapt instrumentation and surgical landmarks from human medicine to a nonhuman primate. The report also reinforces a practical point for clinicians working with exotic species: subtle behavioral changes, including altered mastication, appetite, or pain-related postures, may be the first clues to advanced head and neck disease. (sandiegozoowildlifealliance.org)

The case may also have implications beyond gorillas. If formally published, it could add to the small but growing body of evidence on when aggressive otolaryngologic intervention is justified in nondomestic species, what imaging and surgical planning are most useful, and how teams manage postoperative monitoring when repeat exams require sedation or specialized handling. That matters for zoos, wildlife hospitals, and referral centers that increasingly care for aging or medically complex animals using tools once reserved for human tertiary care. This is an inference based on the reported rarity of the disease, the lack of prior literature, and the precedent set by earlier published gorilla ENT surgery. (sandiegozoowildlifealliance.org)

What to watch: The next step is whether San Diego Zoo Wildlife Alliance and UC San Diego Health publish a peer-reviewed case report with operative details, imaging findings, antimicrobial strategy, and long-term follow-up; in the meantime, the zoo alliance said Mizani is scheduled for another recheck in one year unless new clinical signs emerge. (sandiegozoowildlifealliance.org)