The classic example of this was the 1939 film Jesse James.
One scene in the film involved sending a hoarse over a cliff. This scene ended up killing the horse (not from the fall, but rather the horse later drowned before it could be rescued from the body of water it had fallen into). This triggered condemnation from the American Humane Association (AHA) who ended up working with the Motion Picture Producers and Distributors of America (MPPDA) to establish a code of animal welfare and to monitor said code.
In the 60's the group that the Humane Associated had been working with disbanded and they lost their access to movie sets.

This triggered a 2nd wave of animal cruelty which lasted until 1980 when the movie Heavens Gate allegedly killed several horses during it's production including one being blown up (and several other non-horse issues making it into the film). This eventually pressured Hollywood to allow the AHA to monitor films.

The AHA actually keeps a decent website outlining their cruelty accusations. For example here is the entry for Heavens Gate