Snubbed by a Snob (1940)

A young horse says hi to little donkey Spunky. But the horse's mother pulls him away, saying we don't associate with that kind. Spunky makes a few more overtures, and eventually they set off on a chase, running across a bull from time to time. The horse stops to eat a lot of apples and drink far too much water; this leaves him too bloated to move much at all. The two continue to anger the bull, which gives chase; Spunky saves the colt, and they all live in harmony.

Snubbed by a Snob is an animation movie featuring Jack Mercer.

Snubbed by a Snob is currently streaming for free (ad-supported) on The Film Detective.