Hogle Zoo and University of Utah Health have collaborated to diagnose and treat one of the zoo’s California sea lions, Diego, which fell ill in September 2024. Through a combination of anesthesiology, veterinary science, and advanced imaging, the team identified the cause of the sea lion’s reduced activity as advanced spinal disease and determined an appropriate treatment to alleviate his symptoms.

Animals can’t tell a doctor when they’re sick, so supporting animal welfare—whether in a zoo or in a research environment—requires careful observation. When Diego’s care team noticed that he was moving and eating less than usual, they immediately started working to find the cause of his symptoms.

First, a team of zookeepers, veterinarians, U of U Health partners, and a seal anesthesia expert did bloodwork and an abdominal ultrasound in Diego’s habitat. The initial results came back normal, which ruled out several concerns but left the cause of Diego’s symptoms unknown.

The next step? Getting a 650-pound sea lion into a CT scanner. With his care team by his side, Diego was carefully moved to the U of U Health radiology department. Under anesthesia, Diego’s vital functions were manually supported by his team, who delivered breaths through a large oxygen tank during the transfer.

U of U Health radiologists then led a CT scan of the sea lion’s entire body to diagnose him, finding creative ways to support his body—which was longer than the entire CT scanner table—throughout the imaging process.

The scan revealed that Diego had degenerative disc disease, a spine condition that involves narrowing of vertebral disc spaces, narrowing of the spinal canal, and bulging discs. While serious, this condition is treatable.

Since being diagnosed, Diego has started taking anti-inflammatory steroid medications to ease his symptoms, and his care team has adjusted his training to avoid stressing his spine. He has now started moving around more and has even gone for a short swim. These improvements in care were only possible through collaboration between keepers, veterinarians, and U of U Health imaging experts.