Continuity mistake: When the camera pans in on the two saloon doors at the start of the cartoon, you can see there is a spittoon by the doors marked "Beer." But when the wolf arrives in his car later on, the spittoon is nowhere to be seen.
Continuity mistake: When Lou says to the wolf's eyeballs, "You bother me!" they go back into the wolf's eyes and you can see there is nothing on the table. In the next shot, a glass suddenly appears.
Continuity mistake: When the wolf arrives at the saloon, he goes to the counter and puts his bag of money on it. In the next shot, the bag has disappeared.
Continuity mistake: When we see Droopy gambling at the fruit machine, you can see the fruits have nothing around them but in the next shot a pattern suddenly appears.