Alice's Mysterious Mystery 1926

Directed by Walt Disney

A mouse and his boss pose as dogcatchers and grab a schoolhouse full of dogs; they use several other ruses to round up dogs for, as we discover, a sausage factory. Alice and Julius are on the trail soon after the first caper, but it takes them a while to catch up with the bad guys. They do, and Julius tricks the big boss into getting clobbered by the sausage guy, then turns the dogs loose on him.