Pete's screams alerted Benjamin Spalding to a crisis in the backyard. A fox had grabbed the 34-year-old mealy amazon parrot as he was climbing up the side of his aviary and torn off his left foot.

Spalding and his wife, Stacey Gehringer, of Allentown, wasted no time in getting Pete to Penn Vet's Ryan Hospital, where La'Toya Latney, service head and attending clinician in exotic companion animal medicine, and the emergency team were waiting.

Latney and the team worked to stop the bleeding and provide fluid therapy for their patient. Then they sedated Pete to tend to his wounds. His left leg was severed midway below the knee and he had a small wound on his chest.

The next morning Pete had a computerized tomography (CT) scan to check for further damage.

"With this imaging, we were able to see the full nature of Pete's injury, which really helped with surgical planning," Latney said. "We got Pete into surgery within 48 hours."

Surgeons cleaned out the damaged and infected tissue and closed the wound.

With the short-term crisis under control, veterinarians looked to address a long-term issue common to birds of Pete's size, which often experience pain and develop arthritis in their remaining leg.

Latney assigned Jonathan Wood, staff veterinarian in neurology and neurosurgery, to design a prosthetic leg for Pete.

"I wanted to see what we could do for Pete with 3-D printing," Wood said. "We think about animals that will rehab well and animals that will rehab poorly, similar to people. If there was a parrot that wanted to use what we made for him, Pete seemed to be a good candidate."

The group, which now included Stephen Smeltzer, digital fabrication manager at PennDesign's fabrication lab, and Gregory Kaiman, a fourth-year student, set out to create the leg. The group also needed to figure out how to attach the prosthetic so that Pete, a type of parrot that can live 60 years or more, would be comfortable.

The initial prototypes had the look of a real parrot foot but could not support Pete's weight. The next set of prosthetics, which resembled walking boots, were more stable.

Pete "didn't bite at it, he didn't try to tear away at it," Latney said. "At points when he felt stable, he would actually bear weight on it."

But the leg slipped off when Pete lifted it, so the design team had to go back to the drawing board. It hopes to have a new model for Pete to try out soon.

This time the team is designing a boot for Pete to rest his amputated leg. Team members are also crafting a prosthetic that will secure itself to Pete's stump. One option is a "flight vest" that would go under and around his wings. Another idea is a boot with a socklike rim that would compress around the parrot's leg to keep it in place.

For now, Pete is home with Spalding and Gehringer, who help him with physical therapy on his remaining limb.

"It was fantastic to see Pete using something that we had made," Wood said. "This experience changed our thinking about how to approach other amputees."