I watched a service animal program over the weekend called Tails of Valor. One of the tales featured a B&G Macaw who had splay legs. He was a service bird for a veteran who had PTSD, who got him from an avian rescue. It showed their interactions, which were very loving and quality-filled.
The veteran went on to volunteer at the bird sanctuary. Volunteers would bring the birds on outings to bring some variety into their life. In the process people would stop and ask questions and it gave the volunteers the opportunity to tell them about the sanctuary.
At the end the narrator talked about people with PTSD and service birds. Apparently birds are the best with helping people who have PTSD because they provide their owners with a sense of security.
It's Season 1, Episode 18 if anybody wants to hunt it down. I did a quick search but didn't have any luck.