Guns of Diablo is a Metrocolor 1965 Western directed by Boris Sagal, starring Charles Bronson, Susan Oliver and Kurt Russell. Charles Bronson is a wagon scout (Linc Murdock), who runs into difficulties when he meets old flame Maria (Susan Oliver), now married to corrupt lawman Rance Macklin (Jan Merlin).
There were horses in the Guns of Diablo movie.
The statement is definitely correct as, being a western, horses would have been a large part of the scenery and used widely by cowboys, lawmen, and carriages.