Wearing a red, white and blue vest, Chief never leaves Aaron Mixell’s side. Mixell, an Army veteran, was paired with his service dog Chief through Patriot Paws, a nonprofit that trains and provides service dogs for disabled veterans.
Chief can do everything from opening doors to comforting Mixell in moments of stress.
Each year, Patriot Paws places between 10 and 15 dogs with veterans. Over the past 14 years, nearly 200 dogs have been trained and paired by the Texas-based group. It costs about $35,000 to train a dog, but the program is completely free for veterans. The nonprofit receives most of its funding through private donations and grants.
Learn more about Patriot Paws and how you can help by watching the video above. 
More: 30% of Veterans Suffer From Ptsd. Science Says Yoga Will Help Them Heal