A woman who rescued a drowning dog whose lead was tied to a rock said the ordeal was "horrific" and "emotional".
Jane Harper had been walking her dogs with a friend when they spotted the Belgian shepherd in the River Trent.
The animal, whose name was recorded on her microchip in 2010 as Bella, was taken to a vet where she is recovering.
A 31-year-old woman and a 32-year-old man arrested on suspicion of animal cruelty offences have been released under investigation.
Mrs Harper and her friend Joanne Bellamy found Bella near Long Lane in Farndon, Nottinghamshire, at about 08:20 GMT on Monday.
"It looked like a dead dog, and then it blinked so I got [Joanne] to hold my dogs and went in," said Mrs Harper. "Adrenaline just kicked in and I had to get her out.
"We thought she might have just got caught in the river but it was only when I tried to take her out I couldn't move her.
"The water was so murky you couldn't see the rock at first. It was horrific."
Mrs Harper said the dog had managed to rest its head on a rock to breathe and she pulled her out of the water onto a step.
"She's a big, heavy dog. Then another dog walker came and got her on to the grass, and wrapped her in his jumper. Another lady came running out with towels. It was a real community effort.
"She was absolutely frozen - we all thought she would die. It was very emotional."
Nottinghamshire Police said inquiries continued.