Paolo Miamoto may be known for fixing human teeth, but he is perhaps most proud of giving Vitória the goose her smile back.

When the greylag goose was dropped off at a animal rescue center near São Paulo, Brazil, in December 2015, she was missing most of her bill. Volunteers at Friends of the Sea fed her baby food, but the process was time-consuming and left the bird completely dependent on her human caregivers.

So the rescue center contacted Miamoto, a local dentist who specializes in 3-D facial and dental reconstructions, to make Vitória a prosthetic beak made from a 3-D printer. (Also see "Amputee Tortoise Gets Moving With Wheels.")

Miamoto is part of a group called Animal Avengers, which consists of an all-volunteer crew of veterinarians, 3-D computer modeling experts, and Miamoto, who create custom prosthetics for wild and domestic animals using 3-D printers.

Second Chance

View Images The goose's first surgery, in which she was fitted with a prosthetic beak, went well. Courtesy Animal Avengers 3D

The first beak wound up being too big and falling off. So the Avengers returned to the drawing board on their computer and designed a second prototype, also printed with a type of biodegradable polymer made from corn and sugarcane.

Vitória’s new beak fit perfectly after a second surgery to attach it, and the goose has now returned home to the sandy beaches of Ilha Comprida.

“We give many animals a second chance. Without these prosthetics, most would have been euthanized because there was nobody to care for them,” Miamoto says.

View Images Vitória's first prosthetic, which was too large, eventually fell off, leaving her injury exposed. Courtesy Animal Avengers 3D

It sounds expensive and high-tech, but the process is actually substantially cheaper than building each prosthetic by hand, he adds. All the Avengers need are cell phone photos, open-source computer software, and a 3-D printer. (See "Improving 3-D Printing by Copying Nature.")

And they make sure their creations fit with the animal's behavior and habitat.

“If you give a toucan a white beak, it might be rejected by other toucans. So it needs to be orange,” he says.

View Images After the first prosthesis (left) failed, the modelers and veterinarian went back to the drawing board and created a better fit. Courtesy Animal Avengers 3D

More and more, veterinarians worldwide are turning to 3-D printing as a way to make customizable prosthetics or orthotics for pets and wild animals. Here are a few animals who, like Vitória, are back on their feet with their own printed prosthetics.

Holly the Horse

In Australia, Holly had developed laminitis, a painful, potentially crippling inflammation of the tissues that connect the hoof to the foot bone. Her veterinarian contacted John Barnes, then director of high-performance metals technologies at CSIRO, who 3-D printed the horse a titanium curved horseshoe.

“I had no idea if it would work. I had only ridden a horse once,” Barnes says. But his horseshoe worked, taking the pressure off the inflamed area and letting the horse walk again.

Scientists 3-D Printed a Tortoise Shell Fred the tortoise battled starvation and pneumonia after losing her shell in a bushfire. See how scientists stepped in.

Cyrano the Cat

The 10-year-old orange tabby, which lives in Virginia, survived bone cancer, but the disease severely weakened his knee joint, causing pain. Veterinarians at North Carolina State University used 3-D printing to create a full knee implant. A team attached a new knee—the size of a tube of lip balm—to bones in his upper and lower leg, giving him a full range of motion.

View Images Denis Marcellin-Little explains how he will give Cyrano a replacement knee. Photograph by Becky Kirkland, North Carolina State University

Derby the Dog

Derby, a Malamute, was born without fully formed front legs. The dog couldn’t walk, let alone run. With the help of Derby’s foster parents, a Virginia-based company, Animal OrthoCare, created a special set of 3-D printed prosthetics for the canine. Now Derby races through his neighborhood just like a normal pup.