 Even though animals in cartoons often behave with " semi @-@ human awareness " , Groening said he preferred animals in cartoons to behave exactly the way they do in real life , claiming that this was how animals were depicted in " Two Dozen and One Greyhounds " . Mirkin said there were some exceptions for gags , but most of the time they tried to keep the animals acting realistically . The animal noises for the episode were performed by Frank Welker , who was praised by Mirkin on the DVD audio commentary for the episode , saying , " He can do anything , and it fits perfectly . You forget you 're listening to a guy , and he 's a pleasure to work with . " Welker was also praised by Groening , who said Welker was unbelievably good at doing animal noises . 
