ITV boss Peter Fincham has admitted Britain's Got Talent should have made its winning act's use of a stunt double dog "clearer", calling the way it was presented "a judgement call".
Matisse the dog and trainer Jules O'Dwyer won Sunday's final, but she later revealed it was her other dog, Chase, in the act's tightrope section.
Fincham said: "In hindsight... it would have been better if that was clear."
Ofcom has received 365 complaints over the act, with another 130 made to ITV.
Some outraged viewers complained on Twitter of being "misled" after they voted for Matisse to win. Figures have shown the dog act won by a 2% margin, getting 22.6% of votes compared with 20.4% for magician Jamie Raven.
Fincham said those watching the programme and who were familiar with O'Dwyer's act would have known she had more than one trained dog.
"In the semi-final it was made quite clear the other dog played a role in it," he told the Voice of the Listener and Viewer's spring conference.
"In the audition it was made quite clear this was a dog act with a range of dogs. In hindsight, in the final it would have been better if that was clear."
Judge Simon Cowell admitted he "felt like a bit of an idiot" when he found out Chase performed the trick.
"The moment I found out I literally put my head in my hands," he told the Daily Mirror.
"I spoke to a lot of people after, and I did raise my voice. But it was mainly people owning up to it. They felt embarrassed, they felt frustrated, they felt stupid but you've got to man up to this stuff.
"The producers are absolutely gutted. I was so depressed for the show, for Jules and for the producers themselves, because they are not horrible people."
The show's producers said: "We are sorry if this was not made clearer to the judges and the viewers at home during their final performance."
An Ofcom spokesman said the complaints will be assessed before it decides whether to investigate.
'Scared of heights'
On Monday O'Dwyer said she was "shocked and surprised" by viewers' reactions, saying she used the second border collie to walk the parallel ropes because Matisse did not like heights.
"I was disappointed when people said I allegedly hid Chase and I was trying to make it like Chase was Matisse. That's not so," she said.
"I introduced Chase in the semi-final, and I said 'Chase is Matisse's best mate'. Why put the pressure on the dog when I already have another dog who can perform it on television?"
More than 13 million viewers watched the final, the highest rating for a final since Pudsey the dog won in 2012.
Matisse and O'Dwyer's prize includes a spot performing at this year's Royal Variety Performance and £250,000.