Los Angeles, Jan 21 (IANS) No dogs were harmed during the shoot of "A Dog's Purpose", says W. Bruce Cameron, co-screenwriter of the film which was made controversial by a leaked video from on set.Cameron -- also the author of the book "A Dog's Purpose" -- in a statement issued on Friday, said that the commentary accompanying TMZ's leaked video of a German Shepard, mischaracterises the incident, reports variety.com. TMZ's story began with the audio -- "One of the dogs in the upcoming film 'A Dog's Purpose' desperately resisted shooting a risky scene, but chilling footage shows filmmakers apparently forcing the animal into rushing water."Cameron admits that mistakes were made on the set, but says TMZ's version of the events isn't accurate.He said: "I found the video we've all seen to be shocking because when I was on set, the ethic of everyone was the safety and comfort of the dogs. If the people who shot and edited the video thought something was wrong, why did they wait fifteen months to do anything about it, instead of immediately going to the authorities?"I have since viewed footage taken of the day in question, when I wasn't there, and it paints an entirely different picture."Cameron said the dog, named Hercules, balked at doing the stunt because of the location.He said: "The written commentary accompanying the edited video mischaracterises what happened. The dog was not terrified and not thrown in the water."Cameron also said: "I celebrate animal rescue and am proud of the values that show up in ‘A Dog's Purpose'."Earlier on Friday, a petition was launched calling for a boycott of the family film -- a day after its premiere was cancelled -- unless the creators donate a "significant" portion of the proceeds to animal welfare organisations."A Dog's Purpose" is directed by Lasse Hallstrom and based on Cameron's 2010 novel about a canine who is reincarnated into several dogs over the course of multiple lifetimes.