LAFAYETTE, Ind.  —  Purdue University students are working on an "exoskeleton" for dogs — a type of brace they hope can help older canines struggling with hip problems.

The students came up with a device that fits over part of a dog's back and helps it put more weight on its back legs while using less pain medicine.

"If we can make a joint on the outside of the body to do the same thing, it can reduce pain. We want to make it marketable for all dogs," said Jim Bergren, a Purdue senior in mechanical engineering working on the device.

Some dogs suffer from hip dysplasia, a condition in which the hips deteriorate, making it difficult for dogs to walk without pain.

Although total hip replacement is a common procedure for some afflicted dogs, surgery for older dogs can be risky. Pain medicines are sometimes the only option, but they can damage a dog's liver and kidneys.

To try to help these canines, students in a Purdue mechanical engineering senior design class created the device last year. But this year a new class is trying to perfect the brace by making it lighter, stronger and more comfortable for dogs to wear.

Students and researchers from the university's School of Veterinary Medicine tested the brace Tuesday on Stella, an older dog with hip dysplasia that struggles to walk across a room without pain medication.

Stella wore several reflective balls at her joints and walked in front of a camera — a test meant to measure her gait. A computer will process the reflections to show how well her joints functioned with and without the brace.

Friday, researchers will do the same tests with Stella without pain medication to see how the brace affects her walking ability then.

Gert Breur, lead researcher and professor of small animal orthopedics and neurology at Purdue, said the device could improve the quality of life for older dogs struggling with hip dysplasia.

"If it's severe, they can get lame," Breur said. "It can cause debilitating problems."