You guys are so great at finding stories, I was wondering if you could find this one. Tony becomes aware of just how much Steve is suffering from PTSD, so he gets him a Service Dog - special trained to help returning veterans. (I'm not sure if it's a Service Dog or a Therapy Dog. They are little different.)
I know I read this back when I first started in this fandom (sometime after The Avengers came out,)
Sorry - I don't remember if it's slash or just friendship.
Thanks for the help!