Animal lovers know how difficult it is to see your pets slow down. And when it happens at just barely past the puppy stage, it's even harder. That's Dasty's story. Dasty is a Chicago Police dog, sniffing out guns, drugs, and cash in the organized crime division. But a year ago, he was headed for retirement after being diagnosed with Lyme disease.

(Officer Marion Anderson getting Dasty out of the squad car)

Ofc. Marion Anderson/Chicago Police Deptartment "He lives with me 24 hours a day 7 days a week."

Dasty the German shephard, and Chicago Police Officer Marion Anderson, are a team. "Oh Dasty is a wonderful dog. He is a very happy-go-lucky very sociable dog. Good in the house, good with my family, and good actually with all the other animals that I have."

"There's a lot of time and money involved in a dog. These dogs are very valuable to us," says Officer Steve Martinez.

Officer Martinez is Dasty's trainer, and works with the Pantera, the Chicago P.D.'s first shelter dog. "They see us get dressed for work and they're all excited and we tell 'em see you later I'm going to court today. You can just see the happiness drain out of em. But you're not taking me?"

"ah ah ah, sit, stay"

It's Officer Martinez's job to keep the canine officers sharp.

(Video shows Dasty going through drug drills)

But last year... the officers saw Dasty slowing down and limping.

Officer Anderson recalls the night she knew her dog was in trouible. "It was early in the morning, sound asleep laying next to me and he attempted to move and he let out a big yelp, very loud that he was in very very severe pain."

"I don't see Dasty every day so it was more obvious to me," recalls Officer Martinez.

(Veterinarian video showing Dasty limping and struggling to get up)

Dasty was taken to Arboretum View Animal Hospital in Downers Grove where he was diagnosed with severe arthritis caused by Lyme disease . Dr Cheryl Adams was his veterinarian. "Him finally ending up in a cage was just not an acceptable outcome for any of us."

Veterinarians prescribed high dose steroids which caused dangerous side effects. Dr. adams recommended a stem cell transplant.

"Knowing that none of these traditional approaches were working for him, this was really the option that we had left to us to try and get his quality of life back where it belongs. We remove fat, their own fat from their body. One in 50 cells in fat is actually an adult stem cell."

The vials are shipped overnight to Vet-Stem Inc. near San Diego. Dr. Adams describes what's done at the lab.

"They process the fat. They take the adult extract the adult stem cells out they make them very concentrated. They put them into syringes and they ship them back to us."

Dasty became his own donor and after a series of 3 injections and some physical therapy... Officer Anderson saw a new dog. "What a tremendous change in him, tremendous change. He went to a very lethargic dog to being almost like a puppy again. No problems, no issues going up and down stairs, no issues getting in and out of cars, and his working ability is still as good as it was when he first started. He does have arthritis, he'll need to deal with that long term. But, I would expect him to have the same career as a service dog as he would have before."

Video shows Officer Martinez running drills with Dasty. "Today we ran Dasty thru five narcotics scenarios... ran 'em one after the other and still run around and wants to do more. Dasty's back!"

"Good boy."

Dasty sits when he finds what police are looking for.

"good boy"

Not bad for this comeback canine!

Officer Anderson is thrilled to have her partner back. "We work 5 days a week and he's just laughs tremendous! Oh, I think he's gonna be around for quite some time!"

(Dasty circles Officer Anderson and barks 3 times) "Bark- bark bark!"))

Vet Stem treatments are available to the public. And the company claims an 80-percent rate of success with arthritis. Dasty's treatment cost between four and five thousand dollars, though the bill was discounted because he's a service dog. But, Dasty's earning his keep. Since he's been back on the force, he's recovered several hundred thousand dollars worth of cash and cocaine.