Sometimes, Stephane Marcotte has learned, the best medicine is a dog.

Marcotte left the Canadian military with an operational stress injury after a 28-year career that included "many bad experiences."

As he skirts the details of the traumatic events he saw and the nightmares and insomnia that followed, his companion Sarge, a large yellow labrador, watches him closely for signs of distress.

"What he's actually doing right now, he's grounding me," Marcotte said. "He's going to jump on me and make sure I'm down to earth."

Sarge will be on hand with Marcotte at a fundraiser called Pet Pictures with Santa Dec. 2 and 3 in Saanich in Greater Victoria.

The event will raise money for Vancouver Island Compassion Dogs, a group based in Qualicum Beach that trains canines to help people with disabilities, including post-traumatic stress disorder.

After a nightmare-inducing experience on board a submarine, Marcotte tried treatment with medications but quit, because he hated feeling numb and unresponsive.

He said he was "not doing too good" when he attended an event for servicemen in 2015 that included a booth promoting Vancouver Island Compassion Dogs.

"A lady with a brown lab was there," he said. "The lady said hi to me and the dog just came and licked my face, and I started to cry."

"It was then that I said, 'that's what I need'," Marcotte said. "That lick on my face was like two years of therapy."

It prompted him to begin the process of getting his own service dog.

Marcotte said Sarge has turned his life around.

"Sometimes when I have a flashback or a nightmare he will just jump on the bed and he'll just poke me," he said. "Make sure I'm awake. If I'm not then he will jump and just lick me."

With files from Michael Tymchuk.