I was playing Skyrim on my Nintendo Switch, and I was in Fort Dawnguard. I was about to go up one of the staircases, but I put my Switch down for a second and accidentally shot my stray dog with the crossbow I had equipped.
He was alive, so I made sure he didn't turn on me. He didn't, so I went up the stairs and onto the roof. I saw him follow me up the stairs, but I'm not sure if he followed me onto the roof. After a while of looking around, I jumped over the wall and down to one of the lower roof platforms. When I went back, I couldn't find him anywhere.
I tried buying a troll, I tried recruiting Sceolang, I tried fast traveling, I tried waiting, and nothing worked.
Best Answer
'Stray dogs' are easily lost (as their name implies).
Your only options, seemingly, are to
recruit the dog Meeko, as this will get rid of your current (unfindable) companion:
Meeko can be found "by the road to the south of Meeko's Shack in Hjaalmarch".