The dog, Old Yeller, although described in the dialogue as a mongrel, is portrayed by a Yellow Labrador Retriever and, in the book by Fred Gipson, is a Black-Mouthed Cur, a similar looking but less bulky breed.
A print ad from the Los Angeles Times on Tuesday, February 11th, 1958 shows that this film was widely distributed on a double bill in 21 area theaters. Most of the indoor theaters co-featured Ambush at Cimarron Pass (1958) starring Scott Brady, and all of the drive-in theaters co-featured Underwater! (1955) starring Jane Russell and Richard Egan.
In the Friends episode "The One Where Old Yeller Dies," Phoebe said her mother always turned off the movie after Old Yeller saved the family from the pack of wolves. She never saw the part where Travis had to shoot Old Yeller until she saw Monica, Rachel, Ross and Richard watching the movie.