Continuity mistake: When Spike enters his kennel, there is a bowl beside it. When he looks out of the kennel and sees the cockerel, there is no sign of the bowl.
Continuity mistake: The boot that Spike throws at the cockerel was not on the straw when he first entered the kennel.
Continuity mistake: When Spike grabs the bomb (painted as an apple) from the cockerel, he takes a bite out of it. You can see that when Spike is about to eat it, the eaten part of the bomb is facing his mouth, but in the next shot the eaten part is now facing downwards.