I Love Lucy - Season 6 Episode 14 -

The Ricardos' apartment begins to resemble a pet shop when Little Ricky gets a puppy. Lucy and Ricky are both determined to get rid of the puppy after their son brings it home -- as are their landlords, Fred and Ethel. They have a hard time overcoming Little Ricky's arguments that a puppy would be a welcome addition to a home that already boasts a canary, a frog, a lizard, a turtle, and some goldfish.