I saw that in the theater, too!
I think it was either Old Yeller , or Big Red.
I remember seeing The Black Stallion but that would make me 5 months old at the time. So, it must’ve been released again at a later date. The other movie I remember seeing in the theater was On Golden Pond. What a strange choice to bring a 3 year old to that film.
I saw him in Summer season at Blackpool-many moons ago,
Tarzan or one of the John Wayne black and white war movies. That was a long time ago!