Continuity mistake: When the mice assemble together by the cactus to decide who will get the cheese, their positions change between shots.
Continuity mistake: At the beginning of the cartoon, there are four mice behind the wired fence, but when one of them says "Pussycat!" we cut back to the mice and there are now five.
Continuity mistake: When the crowd of mice await Speedy's arrival, you can the egg box used as the "El Cheese Bowl" has "EGGS GRADE A" on the front. But when Speedy returns with a piece of cheese, the front of the box now says "EGGS."
Continuity mistake: When we see the four mice at the start of the cartoon, you can see there is nothing behind them, but when the camera pans in on them in the next shot, a cactus and a huge rock appear from nowhere.
Continuity mistake: When Manuel takes off his sombrero to give to the other mice, you can see he has a straw in his hand, but when we see Manuel in the next shot, the straw is nowhere to be seen.