Factual error: When Bud-dha is meditating one morning, to his left is the way they came from, and to his right is the way they had been headed the day before (which they say is true north). But, He's facing the sunrise. The sun rises in the East, not the West, so the sunrise should be behind him. Then, after that, when the puppies set off again, they head towards the sunrise, though they're supposed to be headed "true north".
Continuity mistake: Grim falls on Denning, causing him to fall face first in the mud in the pig pen. When Denning stands up, he wipes his face with his hands, but there is still a lot of mud on his face. After they climb out of the pig pen and walk into the barn, Denning still has mud on the side of his head, but the mud is off the front of his face.
Continuity mistake: Rosebud pulls Sniffer's tail to wake him up, but in the next shot, she's back with her brothers, but you never heard any sound of paws.
Continuity mistake: After the puppies have been caught by Denning and Grim, Buddy and Molly are looking at the donut and there is obviously bite marks in it and not all of the donut is there. but, in the close up of the donut, it looks to be untouched.
Other mistake: Denning and Grim are chasing the puppies through a field and their car runs out of gas. They sit there and talk for a few seconds and then they get the net, though in the next shot, when they are chasing the puppies on foot, they are only a few steps behind them.
Continuity mistake: The goat headbutts Denning and he flies backwards and all of the hay moves back with him. In the next shot, when his head falls down, the hay is back where it was before.
Continuity mistake: At the beginning of the movie, when Deputy Sniffer is talking about the puppies, Noah gives Budderball dog food. The food only fills half of his bowl, but in the next shot, the bowl is overflowing.