They saved each other.
In 2012, 4-year-old German Shepherd Axel was two days away from being put down at a high risk kill shelter when he was rescued by K9s for Warriors, a nonprofit organization that pairs canines with military personnel suffering from post-traumatic stress disorder.
After months of training, the service dog was coupled with Marine Capt. Jason Haag to help him cope with his severe PTSD and a traumatic brain injury he sustained in 2010 after serving multiple tours in Iraq and Afghanistan.
“Axel gave me back the ability to be in society and to talk to people again,” the father of three tells PEOPLE. “He wakes me up from nightmares, pulls me out of anxiety attacks and brings me out of flashbacks.”
After getting shot in 2003 and injured by an improvised explosive device in 2008, Haag experienced a prolonged period of depression. A neighbor recommended looking into K9s for Warriors for help.
“I had cut myself off from everybody and I was stuck in my basement for a very long time,” he says. “I had reached my breaking point.”
After seven months of communication with the organization, Haag met Axel for the first time during a three-week training session.
“It worked right away. The first thing I did when I got back from training was go to my son’s baseball game,” says Haag. “That was the first event of my kids’ that I’d been to in two years.”
Axel, a “big crazy puppy who is loving and caring,” recently pulled Haag out of a particularly painful flashback by licking his face and nudging his arm when a July 4th firecracker caused the Capt. to fall to the ground, “crying, screaming and yelling.”
“He’s my best friend, we go everywhere together. He’s in sync with me it’s pretty unbelievable the way he can just tell what mood I’m in and what mood he’s in,” says Haag. “We’re dependent on each other. He saved my life, without a doubt. I think he knows that we saved his life as well.”
For more on Axel and other hero dogs, pick up the latest issue of PEOPLE on newsstands now.