there is quite a few and 2 much to list them all but here are a couple:rottweiler, mastiff, kelpie, damchi, sheepdog, broholmer, aidi, halden hound,boxers, pitbulls, bulldogs, pugs, sibrarian husky,...
Well, if the mother were a dachshound and a lab (i know unlikely, but just go w/ it) and the dad was a terrier, then, yeah. I would consider that to be a three breed dog.