O’Dwyer, who trains guide dogs, told ITV’s Lorraine show that it was another dog called Chase who walked the tightrope because Matisse is afraid of heights.
The sketch featured O'Dwyer dressed as a policewoman going after Matisse, who had stolen sausages from a butcher, and also featured another of her pets, three-legged Skippy.
Viewers saw Matisse emerge back on to the stage after he appeared to have walked along parallel ropes, but it turned out that a second border collie had performed that part of the stunt.
O'Dwyer said: “Matisse is a little bit afraid of heights so, although he could physically do it, Chase is the dog who says 'I'm the action dog'. He plays the double for him. Every dog has a different character.”
She added: ”The tightrope takes months of training. It takes a special rigging system. It takes professionals to help you. BGT were fabulous. Our team said what we needed to pull this off.”
But others were less at ease with the decision to use an unnamed stunt dog:
Britain's Got Talent winner 'used stunt dog double' to walk the tightrope. Soo literary they cheated..... #CHEATER!!!!!!— JONATHAN M. MELLOR (@JonathanMellor) June 1, 2015
Can't believe the Britain's Got Talent winner used a stunt dog in their performance Can I just send in Prince to sing for me on X-Factor?— Lukehoostawking (@LukeHoosTawking) June 1, 2015
as if it was a stunt dog who won Britain's got talent last night— pocket tits (@yoimim) June 1, 2015
My issue with this Britain's Got Talent stunt dog farce is it didn't walk the tightrope with any authority or conviction. Amateur stunt dog.— Harry Moore (@Harry_Moore_) June 1, 2015
A spokesman for the producers of Britain's Got Talent said:
“The audience had previously seen from Jules’ semi-final routine that she works with a second dog Chase alongside Matisse. For the final performance, as Jules has said publicly herself, Chase completed the tight-rope walking section of the act.
“During the competition viewers have seen that Jules' act involves a team of dogs, including Chase and Skippy, alongside starring dog Matisse, to perform her unique mixture of dog agility and story-telling. We are sorry if this was not made clearer to the judges and viewers at home during their final performance.”