In November 2006, Dr. Melvyn Pond performed total hip-replacement surgery on a patient who had been hobbled from years of exercise and competition.

Now the patient is competing again  on all fours.

“She’s doing very well,” Pond said of Lily, a 9-year-old pug who participates in agility contests. “For her to be able to run, jump and climb again is pretty exciting news.”

Pond, who is based in New Haven, is among a handful of veterinarians who have been replacing hips, elbows and knees in dogs like Lily, allowing them to prolong their competitive careers.

Joint replacement has helped larger working dogs return to hunting, aiding the blind and assisting in search-and-rescue missions and other police activities, not to mention relieving the pain of beloved pets. Although hip-replacement surgery for bigger dogs has been performed since the mid-1970s, micro-hip replacement for cats and dogs weighing 6 to 30 pounds began in the last five years.