ARLINGTON, Wash. -- Weighing in at a whopping 150 pounds, Harley was bound to have trouble walking at some point. At just three years old, the Newfoundland has already had ACL surgery. Now, arthritis has set in.

“It’s pretty sad,” said his owner, Melanni Craig. “We knew it was time to go in and get him checked out. You don’t want to see him in pain.”

Not too long ago, Harley would've been relegated to a lifetime of daily medications that can cause adverse side effects in a lot of dogs. His vet, however, proposed something completely different -- a stem cell transplant.

“I've heard of stem cell, but not for animals,” said Melanni. “I was kind of surprised.”

Weighing in at a whopping 150 pounds, Harley was bound to have trouble walking at some point.

It's a two-step procedure. First, a chunk of fat is taken from the animal and sent to a lab where the cells are harvested.

On Wednesday, techs at Arlington Veterinary Hospital sedated Harley and hoisted his hulking frame into the operating room where those cells were injected directly into his joints.

The actual injections took all of about 5 minutes.

“When we put a stem cell in an area where there's pain and inflammation, the stem cells go in there and tell the body to heal itself,” said Dr. Jeff Mayo, who performed the procedure.

Prime candidates for stem cell transplants are dogs over 20 pounds with arthritis, hip, joint or knee problems. The procedure is also performed on cats with kidney issues, according to Dr. Mayo.

The operation costs anywhere from $1,200 to $2,500. Success rates are said to be in the 90's, but much of that is anecdotal.

Within a few minutes of waking up from his injections, Harley was back on his feet. His owners hope he'll stay there, pain-free, for many years to come.

The step cell therapy for dogs is a two-step process.