Mariah Carey's husband detailed the joke on his 92.3 Now FM morning radio show on Thursday (10Nov11), claiming the incident had gone awry because the pooch, named Charlie Roo and belonging to his co-host Sarah Lee Owensby, had since gone missing.
Video footage posted on the radio station's website appeared to show a small dog attached to balloons, floating up into the clouds before disappearing from view - and campaigners at People for the Ethical Treatment for Animals (PETA) lashed out at Cannon.
PETA President Ingrid Newkirk raged, "If bad taste were a crime, we'd be going to jail with Nick, but joking about killing a dog, a kid, an old person - anyone - isn't cool when there's always the danger that some numbskull will do it for real."
But Cannon has played down the stunt, insisting he "really loves dogs" - and revealing the prank involved a stuffed animal, not a real pooch.
In a video shot prior to the incident, he says, "I won a bet with Sarah Lee, and I'm about to play the meanest joke on her ever. This whole time I've been acting like I don't like dogs, but I really love dogs. I'm a dog person... But I'm pretending that I want to float Charlie Roo with balloons!
"I'm not really gonna float a dog. I'm gonna float a stuffed animal that looks just like Charlie Roo."