Bella, a German Shepherd dog, was tied to a large rock before being spotted by passer-by near Long Lane in Farndon on January 6 last year.
She was rushed for emergency veterinary treatment and it was there that her microchip was found which was registered in 2010, and gave her name and owner’s details as Charlene Latham.
Latham was sentenced to a 12 month community order after she pleaded guilty to causing unnecessary suffering to Bella by attempting to drown her.
Bella was transferred into the care of the RSPCA Radcliffe Animal Centre in Nottingham while the police and animal welfare charity launched an investigation.
A vet who examined Bella after she was pulled from the river said had she not been treated when she was then she would have died.
The beloved dog, who was ten-year-old at the time of the ordeal, had since recovered after being nursed back to health by the RSPCA, and had been living with her new owners Maggie Mellish and Charlie Douglas in Derbyshire before her death.
The RSPCA said Bella had "long-term health conditions" and had to be put down.
In a Facebook post, RSPCA Radcliffe Animal Centre where she had been looked after while the charity and police launched an investigation to find who was responsible, said: "It is with a heavy heart that we bring you the sad news of Bella’s passing.
"Our beautiful and courageous friend was peaceful at home with her owners.
"We have been truly blessed in caring for her and proud to have been part of her story."
They said: "We will be ever thankful to her owners Maggie and Charlie for welcoming her into their home our amazing team dedicated to her recovery and of course to Jane and Joanne her heroic rescuers."
The Radcliffe Animal Centre added they were "truly blessed" in caring for her and "proud to have been part of her story.
"We will remember Bella as happy in her new home surrounded by love, kindness and respect."
"That is all we ever wanted for her and we are comforted that this is where she found peace and was finally able to let go. Love to you always Bella, you will never be forgotten."