Goof: The layout of the Ricardo master bedroom is different than in previous episodes due to the changing of filming studios. Someone placed a wall lamp next to Ricky's bed where there should be a window.
When Lucy is yelling at the yipping dog that it's 3:00 AM, and shows the dog the clock, you can see that the time isn't 3:00. It looks more like 2:20.
Evidently, this "no pets allowed" rule didn't affect Mrs. Trumbull, who used to babysit Little Ricky. In episode #100, "The Business Manager," she asks Lucy to go to the market and buy food for her pet cat. The Mertzes also had a dog named Butch who's only appearance was in episode #4, "The Diet."
Lucy: Oh now, honey. Listen, I'm sorry, it's a very sweet little puppy, but I'm afraid we're not gonna be able to keep it.
Little Ricky: Why not?
Lucy: Well, for one thing, dear, our house is too small for a dog.
Little Ricky: But, Mommy, it's a small dog.
Lucy: Well, I know. But he's gonna grow bigger.
Little Ricky: Maybe our house will grow bigger, too.
Lucy: Hey, speaking of our new neighbors, are there any little children Ricky's age?
Ethel: No. It's a bachelor--Mr. Stuart. But he's an old grouch.
Lucy: Why would Fred rent to an old grouch?
Ethel: Well, to one old grouch, another old grouch doesn't seem like an old grouch.
Ethel: Well, I'm going on to the market, honey. You want anything?
Lucy: Well, not for us, but, uh, Alice and Phil could use some birdseed, and Tommy and Jimmy could use some turtle food, and Mildred and Charles could use some fish food.
Ethel: Wouldn't it be easier if they just ate each other?
(It's late and Little Ricky's dog is barking)
Ricky: You go! He's your son's dog.
Lucy: My son? Isn't he your son too?
Ricky: Not at 3 o'clock in the morning, he isn't!
June Foray provided the voice of the yelping puppy. In order for the timing to be perfect the yelping needed to be done live. Foray's voice begins to get hoarse as the episode moves on.
John Emery guest starred as Harold in the first season's episode, "The Quiz Show."
Keith Thibodeaux (Little Ricky) fell in love with the canine actor who played Fred. Because he was so young he didn't realize that it was a trained professional dog.