DENVER -- When her dog, Thor, became a teenager, Jessica LeRoux says she could tell the years were taking a toll on the black labrador border collie mix.
"His hips were getting rickety in the back, he would be shaky sometimes when he was walking," said LeRoux, who is partly deaf and says Thor worked as a service dog, alerting her to sounds she couldn't hear.
LeRoux believes Thor's arthritis was crippling, leaving him without enthusiasm.
"He just kind of wanted to lay there," she said.
So the self-proclaimed "hippie," who for two decades helped treat willing hospice patients with marijuana-laced edibles, decided to give Thor a different kind of treat.
"When you love your dog... you would to anything, just about anything to make their day better," said LeRoux, who runs a medical marijuana edibles business, "Twirling Hippy Confections," based in Denver.
Jessica gave Thor marijuana treats made specifically for him -- and she says the special ingredient gave him new life in his old age, keeping him active until he eventually passed away at 15.
"He really showed marked improvement in spirit and temperament and liveliness," said LeRoux.
Partly because of her experience with Thor, she began treating other dogs with cannabis, too -- listing as many as 30 dogs and cats as clients.
She's also working on a prototype marijuana treat she's hoping to bring to market.
"I wanted to make a product that was clearly designed for a dog," she said.
But not everyone is sold on the idea.
"It is so toxic," said Dr. Jenna Ashton, a veterinarian at the VRCC veterinary hospital in Englewood. "We don't know that fine line yet about how much to give our pets for therapeutic benefits versus toxicity."
Dr. Ashton says that over the past few years, since medical marijuana was legalized, the number of emergency room visits by dogs overdosing on marijuana has "probably doubled or tripled."
"Pets are part of your family and you want to do everything for them," she said, but added "I think scientifically speaking we have other pain modalities they can receive that have been proved."
Though Dr. Asthon does admit it is possible that with more research, more veterinarians may someday prescribe marijuana to their dogs.
Meantime, Jessica LeRoux believes she is laying the groundwork for a new angle in the growing marijuana industry.
"People are free to criticize, but every dog I've ever owned has lived to be 15 years old and they've been in excellent health."