Family Guy: 1x7

Brian: Portrait of a Dog

When a heat wave hits Quahog, Peter gets Brian to enter a dog show to win $500 so that the family can get a new air conditioner. When they argue over a trick gone bad, Brian walks out on the family and Peter replaces him with a cat. Brian struggles to assert his civil rights and soon ends up at the pound. Luckily, Peter is able to bail him out by bribing the judge.