Continuity mistake: When we see "Grandpa's Folly" being 'scratched' in his starting box, the box has no door in front of it, but when we see the boxes at the start of the race in the next shot, a door has suddenly appeared.
Continuity mistake: When Bugs emerges from his hole at the start of the cartoon, you can see there is some dirt around the hole, but when we see a close-up of Bugs in the next shot the dirt has gone.
Continuity mistake: Throughout the race, watch the bands on the dogs. In some shots, they have numbers on them: others they don't.
Announcer: The dogs are going into their starting boxes. Now they're on edge for this race. Bill's Bunion looks a little sore. Pneumatic Tire's rounding into shape. Father's Moustache looks a little droopy. Motorman's Glove will have a hand in it. Bride's Biscuit is hard as a rock. Grandpa's Folly is out of it. He's being scratched.