It is revealed that Itchy's cap was given to him by Charlie, who used to wear it himself. This contradicts Itchy's puppyhood flashback in "Fearless Fido", where he is seen wearing it.
Charlie: (watches Itchy doing tricks for his owner) He's not a dog, he's a trained seal!
In the flashback, Charlie uses the same "Whaddya say, whaddya know" line he used in the original movie.
The episode title is a parody of the film When Harry Met Sally....