Prostheses in the Animal Kingdom

After recovering from a nearly fatal injury that caused her to lose her fluke, Winter the dolphin has been given increased mobility by a prosthetic fluke helping her learn to swim in a normal up-and-down pattern. Photo by Clearwater Marine AquariummProstheses have been used on humans with missing or impaired limbs since the earliest civilizations, and now humans are helping non-human animals use artificial aids to supplement their own impaired anatomies. With the advent of new types of prostheses and techniques to create and attach them, animals who may have otherwise perished or been incapacitated are getting a second lease on life.

"Imping," a practice once primarily used by falconers to maintain their birds in a pristine condition, is now performed by raptor rehabilitators as well. Simply stated, a section of a damaged or broken feather is replaced with the duplicate section of another harvested feather—from a deceased bird of the same species—with an adhesive.

In addition to harvested feathers, tools for imping often include dried bamboo to make the "bridge" connecting the two feather shafts, dog nail clippers, a utility knife, epoxy glue, paper and a sharpie pen. These basic utensils allow a skilled raptor rehabilitator to perform the procedure and release back into the wild a bird with a natural prosthesis. When accurately executed, imping results in a feather or even multiple feathers as stalwart and functional as the raptor's previously uninjured flight feathers, and they will stay intact until molted out.

Unfortunately, not all animal prostheses are so cleverly simple, providing animals the opportunity to be released into the wild. However, a synthetic prosthesis may improve the quality of life for many injured animals. Albie the goat, for example, is not your typical amputee. Rescued from the streets by Brooklyn Animal Care and Control officers and brought to Farm Sanctuary in New York, Albie was given a second chance to walk on four legs. He lost the lower half of his left leg last December due to an injury sustained in what is presumed to be a slaughterhouse accident.

Fitted by a certified prosthetist, Albie's new appendage was attached for the first time in early May. His prosthetist, who also fitted another non-human animal six years ago, stated to The New York Times, "I'm not an expert on fitting animals, but I've fitted some complicated humans, so I thought it wouldn't be much more difficult to fit Albie." Albie exceeded expectations with his ease in adjusting to his new leg, and with some minor adjustments, he should be romping across his farm in no time.

Pierre, a 25-year-old African penguin living at the California Academy of Sciences, has all of his limbs intact, but recently began to lose his feathers—leaving him shivering in the cold and apprehensive about taking a plunge with his peers in the chilly waters of their pool. African penguins, also known as Jackass penguins because of the loud donkey-like braying noises they make, only reside naturally off the coast of Africa. Unlike other ocean dwelling animals such as seals or whales, who have blubber to keep them warm, penguins use a thin layer of air trapped underneath their feathers as insulation from the cold on land and in the water.

With his loss of the feathers that keep him warm, Pierre was in need of a remedy. Pam Schaller, a senior aquatic biologist working with the penguins, thought a penguin-sized mini wetsuit might do the trick. A diving gear supplier fitted Pierre for his gear, and fears that the other penguins might reject him were alleviated as soon he waddled around and settled in beside his mate. Pierre's wetsuit was a success, allowing him to swim in the brisk pool water. His feathers have started to grow back, and he will eventually be weaned off the wetsuit.

Winter the dolphin was just 3 months old when tragedy struck. Trapped in a crab trap line wrapped tightly around her tail, she lost valuable blood circulation before being rescued and taken to the Clearwater Marine Aquarium (CMA), which specializes in the rescue, rehabilitation and release of sick and injured marine mammals. Underweight, dehydrated and with the injuries she suffered due to the carelessness of people, the dolphin's prognosis was grave.

To worsen her fate, shortly after her arrival to the hospital, Winter's fluke began to disintegrate and fall off in pieces; within weeks, she lost her entire fluke and two essential vertebrae that power the fluke's up-and-down movement. Thanks to 100 volunteers, staff and veterinarians spending four months caring for the dolphin around the clock, Winter's health eventually improved.

After learning how to propel her-self forward with her pectoral fins and developing a side-to-side swimming motion much like that of a shark or fish, rather than the up-down motion of a dolphin, Winter was introduced to an adult companion dolphin, Panama. Even though Winter had surpassed expectations with her capacity for survival, her unique swimming style raises concern for injuries to her spine.

Then came the idea for a prosthetic fin. With the aid of a top human prosthetics company, marine mammal veterinarians and CMA staff, the collaborative effort paid off. Trainers have spent the last year and a half teaching Winter to swim using the typical up-and-down motion of a dolphin with his or her fluke intact. The new prosthetic is used as a cue for her to swim in this normal pattern, with the objective to maintain her ability to swim comfortably when the fake fin comes off.

In 2005, Beauty the eagle was found in an Alaskan landfill, starving and attempting to scrounge for scraps for a meal. Her top beak had been shot off by a senseless poacher, rendering her incapable of grasping food. Left with a stump that exposed her tongue and sinuses, Beauty was unable to preen her feathers, and the simple act of drinking water had become a troubling hurdle she was unlikely to surpass on her own.

After being rescued from the landfill, Beauty spent two years at a bird recovery center being cared for and fed by hand. Her caretakers hoped her upper beak might grow back, but too much damage had been caused by the gunshot. In 2007, biologist Jane Fink Cantwell brought Beauty to her Birds of Prey Northwest ranch, where she continued the daily hand feedings.

Yet to insure the eagle's survival, a beak was needed, and it would have to be made of artificial material. Fortunately, Cantwell met Nate Calvin, a mechanical engineer who wanted to help. After spending hundreds of hours working to perfect the molds, Calvin was able to create a beak for Beauty. On May 19, 2008, her temporary beak made out of nylon composite was attached in a garage containing an audience of quiet reporters and special guests.

Beauty's more permanent beak, fashioned from titanium, will be attached at a later date. Although she will never be released into the wild because her prosthesis does not allow her to tear flesh from prey, she seems to enjoy tackling freshly cut strips of salmon with her new beak. Beauty's caretakers are also optimistic for her future as a foster mother for orphaned eagles—and agree she is solid proof that humans are not the only species capable of benefiting from prosthetic devices.