Army Sgt. Adam Renteria and dog Rakkasan
Allison Michael Orenstein
03/28/2014 at 05:00 PM EDT
Diagnosed with a traumatic brain injury and PTSD after tours of duty in Kuwait and Iraq, Army Sgt. Adam Renteria, 32, struggled in his return to civilian life.
"I felt this disconnection from everybody and everything – family, friends and from myself," he says.
Though treatment and therapy helped, Renteria found himself backsliding into anxiety and depression upon hearing of the Colorado movie theater shooting in July 2012. "That was a real trigger for me. I got really angry," he says. "I couldn't exist out in public."
At the suggestion of his mother, Gloria Gates, Renteria contacted Pets for Vets
, an organization that seeks to heal the emotional wounds of military veterans by pairing them with shelter dogs specially selected to match the vet's personality. Though Renteria requested "the biggest meanest dog you can find," Pets for Vets founder Clarissa Black paired him with Rakkasan, a 30-lb. Korean Jindo.
"That first night, Rakkasan slept in my bed," says Renteria. "I put my hand on him and fell asleep for eight hours straight – for the first time in years."
Rakkasan now accompanies Renteria everywhere he goes. "My life has a renewed sense of purpose," says the veteran, who's studying for a master's degree in military social work. "And Rakkasan is the biggest part of that."
For more stories of the life-changing power of pets, pick up this week's PEOPLE magazine.