Quahog Pets is where the Griffin Family go to buy a new dog a month after Brian is killed by a car in "Life of Brian".
There, they find Vinny, a "pussy hound" who claims to be 1/16th cat. He wins over Peter by being able to talk and suggests that if he is sent to fetch a stick, he could bring back an iPhone that "fell off a truck" instead.
Brian goes to Quahog Pets in "Movin’ In (Principal Shepherd’s Song)" to find something to make his coat shiny, but runs into an apathetic clerk. While there, he is recognized as the star of a book written by Stewie that portrays him as an idiot.