The night-time rescue came after 17-year old Staffy cross Scorch got away from his owner Colin Howe during a walk along the Llangollen Canal towpath on Monday night.
Although she managed to scramble out of the water, Scorch was then trapped on the wrong side of the bank with Mr Howe unable to find a way of getting to her.
He eventually made the decision to ring 999 at 9.40pm and ask for help from Shropshire Fire and Rescue Service.
"I was too scared to go into the canal myself, I had no idea how deep it was - and I also had my other dog with me," Mr Howe said.
Fire crews from Ellesmere and Baschurch went to the scene and had to walk along the towpath to find Mr Howe and the dogs.
A water rescue specialist firefighter waded to the other side of the canal to rescue the dog.
"The firefighters were brilliant. They had to call up the specialist water rescue crew. I can't thank them enough they saved my dog's life," Mr Howe said.
He said he would be making a donation to the firefighter's charity as a thank you.
Mr Howe is an accountant who travels between clients in Shropshire and Somerset in his camper van with his dogs.
"We walk the canal towpaths around Ellesmere all the time, I just don't know what was the matter with Scorch tonight, he just ran off."