It may be So Quiet on the Canine Front, one of the Dogville shorts from MGM.
There's a Short Films section a little further down on the Genre message boards. There are a few short film experts that can give you a lot more info, I'm sure.
At first I though you were cracking wise and that isn't nice to do to newbie (I have been told since I did it and got nasty PM).
But as usual you're a class act and helped someone out.