Laura Heffron and her 10-year-old dog Tessie enjoy two half-hour walks daily. But one day in June, as they headed out the door, Tessie collapsed. Heffron headed straight for the emergency room, where X-rays showed that Tessie had arthritis in her back left knee.
Heffron knew what Tessie was in for. Heffron had been diagnosed with arthritis in both feet only five months earlier.
"Our X-rays were almost the same," Heffron said, recalling the stark black and white image of joints surrounded by a fuzzy gauze, a hallmark of arthritis.
With one in five adult dogs and 27 million Americans affected by arthritis, according to the Arthritis Foundation, the chances that a person and their longtime pet will both develop the disease are high. Going through arthritis together can be painful, but care -- and commiseration -- can help both pet and owner develop a deeper bond.
"We all slow down as we get older, and a dog is no different," said Dr. Randy Boudrieau, a professor of orthopedic surgery at the Cummings School of Veterinary Medicine at Tufts University.
Arthritis in dogs parallels the progression of arthritis in humans as the cartilage cushioning at the joints wears down, causing inflammation, stiffness and pain.
The most common problem area for dogs is the hips. Other common places for dogs to get arthritis include the knees, elbows, and the spine.
But knowing the course a pet's life is due to take can be an unwelcome realization.
Doug Van Treek, 45, from Chicagoland, Ill., was diagnosed with arthritis at age 10. Growing up, he was not allowed to play contact sports and had to manage his disease with medications.
Age reduced his activity, which included playing and exercising with his two golden retrievers, Taz, 13, and Wrigley, 11. Taz already has arthritis and Wrigley is in the first stages of the disease.
"It's difficult to see your dog go through it just like I did," Van Treek said.
Managing one's own pain and physical limitations alone can be challenging, even without the added burden of managing a pet's symptoms. It can be difficult to watch a dog change its behavior to accommodate its deteriorating body.
"It's sad. I remember her running up the hill to the house and now I see her walking very slowly," said Gail Kershner Riggs, 70, a research specialist at the University of Arizona's Arthritis Center, who has had arthritis since she was about 5 years old. "It really breaks your heart."
But even when a dog does begin to change its behavior to accommodate stiffer joints or pain, behaviors that can include difficulty sitting or standing, less interest in play, or preferring soft surfaces to lie on, an owner may not attribute such changes to arthritis until after a veterinarian's diagnosis, and even then it can come as a shock.
"I don't know that many people talk about [arthritis]," Boudrieau said. "Most clients are oblivious to whether their dogs have problems or not because the dogs don't complain."
Realizing that a loved pet will have to battle the same disease an owner will "can be pretty demoralizing," said Dr. I. Martin Levy, an orthopedic surgeon at Montefiore Medical Center in New York, who also participates in canine agility competitions. "But it can be used as a mechanism for both to recover."