The nine-year-old managed to struggle free and ran up the riverbank, but according to police was "savagely mauled" by a dog as he tried to escape. The dog also attacked the mother as she tried to drown her youngest son, an investigating detective claimed in court.
The dog was seized by the local council following a police order.
But Buddy's owners say he was trying to protect the children, rather than attack them, and believe he should be returned and protected rather than punished.
The Gopetition page, started by the dog's owners and supported by the boys' grandfather, says: "Buddy the dog has reacted and attempted to save the boys in doing so he has bit the eldest boy in his rescue attempts. Unfortunately he was unable to save the youngest boy and has also bit the mother."
The owners say Buddy "doesn't have a history of being a dangerous dog" and has never previously been seized or bitten anyone.
"Buddy is a member of our family and has grown up around children his whole life and has been the most gentlest dog," they wrote.
"He has clearly seen a child in distress and attempted to help."
The petition, which has garnered more than 36,000 signatures, is addressed to the Murray Shire Council who Buddy's owners want to release the dog and "let him come home".
The petition has been backed by the maternal grandfather of the boys, who says he wants to "do everything we can to help save Buddy".
"I own a similar dog, and I know he was trying to save the boys, it's their nature when they are raised with kids," he said.
"Let the ones who his actions affected decide. I have one grandson left, because this brave dog took action as required."
