'A Dog's Purpose' Trainers Deny Wrongdoing, Claim Video Was 'Falsely Edited'

Birds & Animals Unlimited -- the group responsible for training the dogs in "A Dog's Purpose" -- insists Hercules the German Shepherd wasn't forced to perform a stunt, and claims the video doesn't tell the full story.

In a letter to TMZ, the org admits Hercules was resistant to entering the pool from a new location, but they cut right away, and went back to the original spot where he'd trained for the scene ... and he jumped in, happily.

Birds & Animals claims the dog was not thrown in from the spot where he resisted, but feels the "falsely edited video" implied that. TMZ did not edit the video. We posted all the footage as obtained.

The letter also addresses the voice in the video saying, "Just gotta throw him in."