Teaming Up for a Polar Bear X-Ray

September 12, 2018

Preventive care for Lincoln Park Zoo’s animals is a team effort: among Animal Care staff, veterinarians and veterinary technicians, and the animals themselves. Using operant conditioning methods based on positive reinforcement, keepers encourage animals to voluntarily participate in their own care. From a western lowland gorilla displaying its teeth to a harbor seal raising a flipper, this cooperative approach helps caregivers discern minor issues or potentially serious ones that may require intervention to safeguard the animal’s well-being and welfare.

One recent collaboration embodies the effectiveness of this approach—in a very big way. Indeed, there is So Much to Care For.

This past May, Animal Care staff at Walter Family Arctic Tundra noticed a wound on the right, front paw of Talini, a 13-year-old female polar bear who shares the rugged, naturalistic habitat with 8-year-old male Siku. The zoo’s associate veterinarian, Kate Gustavsen, D.V.M., concluded that an x-ray (or radiograph) would be beneficial to diagnose the condition.

“Wounds on digits can occur for many reasons, and a polar bear’s thick coat could hide a deeper problem,” says Gustavsen. “Radiographs can help us make sure there is not a problem we cannot see from the surface.”

Of course, getting an x-ray of a polar bear’s paw is easier said than done, and generally requires anesthesia. But does it always?

Curator of Mammals Mike Murray knew that operant conditioning in the bears’ off-exhibit living quarters would provide the best controlled setting for having Talini interact safely with the vets’ portable x-ray gear. But how? Murray asked the zoo’s facilities staff for help.

Director of Buildings and Grounds Herbie Diaz and Special Projects Manager Rick Cortez created a small “port” at the bottom of the enclosure barrier. They built a protective plastic housing for the x-ray plate, to be placed on the floor just outside the port. Above that they rigged a suspended steel bracket system to which the portable x-ray generator could be attached, thus allowing the veterinary technicians to take the radiograph image from a safe distance.

Using just the port minus the x-ray gear, keeper Valerie Bogie began operant conditioning sessions with Talini in early June, using positive reinforcement (more specifically, raw fish and meat) to encourage the bear to place her paw on the x-ray plate holder. A few weeks later the team hung a painted, yellow cardboard box on the bracket to simulate the x-ray machine. Murray and Behavioral Husbandry and Enrichment Manager Allison Kao helped guide the training sessions. After 28 sessions over 37 days, Bogie and Talini had made such progress that a radiograph was scheduled for July 10. During a final run-through on July 8, keepers wore large raincoats to simulate the lead aprons they and the vet team would have to wear when taking the radiographs. Veterinary technician Joe Ullmer took the x-rays two days later. The procedure went flawlessly.

“Herbie and Rick did a fantastic job of securing the mount for the x-ray generator—it was perfect for our needs,” says Ullmer. “Val, keeper Dana Hunter, and Allison did a tremendous job of getting the bear to provide a behavior that allowed us to get the information needed without an anesthetic risk—especially for Talini. Speaking of whom, a huge thank you to a bear willing to participate in voluntary training.”

Veterinarians reviewed the images and concluded the wound was minor and wouldn’t require any surgical intervention.

“When the problem is minor, and we just need to ‘keep track of it’, it is not in the animal’s best interest to anesthetize it repeatedly,” says Kathryn Gamble, D.V.M., the zoo’s Dr. Lester E. Fisher Director of Veterinary Medicine. “Training allows animals to participate in their medical care and allows us to make better choices. Additionally, when animals are in social or breeding situations, reduced interference helps to achieve those goals.”

The voluntary polar bear x-ray was a first for the zoo, says Murray.

“Incredible teamwork accomplished this, from rigging a polar-bear-proof x-ray plate holder to the rapid success of the keepers’ training,” says Murray. “This process exemplifies how this zoo comes together for animal care.”

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