A terrier puppy had corrective surgery on her front paws that were upside down. Now she's learning to walk.

• A spotted rat terrier was born with a defect that caused her front paws to develop facing upward.
• Veterinarians at Oklahoma State University performed a surgery correcting Siggi's paws.
• Now, Siggi is learning to walk. Her veterinarians have called her a "fairly quick learner," OSU said.

A rat terrier puppy got a new lease on life when veterinarians corrected a birth defect that caused her front paws to develop upside down.

Siggi, whose paws faced upward instead of downward, was rescued as a puppy in Dallas, Texas.

Dr. Erik Clary of Oklahoma State University's College of Veterinary Medicine said that Siggi's elbows were actually the root of her problem.

"For reasons not fully understood, these patients' elbows come out of joint early in life and the result is severe rotation of the lower front limbs and an inability to walk," Clary said in a press release. "At most, they might muster a crawl that seems most uncomfortable and is poorly suited for a dog's life."

In May, Clary performed a corrective surgery on Siggi that involved "an intentional break high up in her ulna bone to de-rotate the limb." Siggi's elbows were splinted to allow them time to heal. By late June, Siggi's vets found that her bones were healing properly and removed the splints, according to the press release.

"At that stage, the task then became one of teaching her how to walk and she proved a fairly quick learner," Clary said, adding that the puppy has learned how to do "many things that puppies like to do, including chasing a ball in the yard."

"Truly, I could not be more pleased with Siggi's progress," Clary added.

Puppies with special needs are often considered less-adoptable, a term that also includes black and senior pets, according to Petfinder, a catalog adoption agencies and pets available for adoption. A survey of the organization's shelters and rescue groups found that it takes up to four times as long for less-adoptable pets to find homes than most other pets.