Old Whitey
Any large white dog that drools to a disgusting degree; also a large white dog that generally gets itself horribly dirty as quick as you can clean them. Can apply to a dog of any age. Can also describe anything that is as gross as the dogs get. Originates from the Great Pyrenees dogs which while they are beautiful tend to get very disgusting and then want to get petted or jump on the couch.
Don't let the old whitey in he will wreck the house! Did you see how gross that guy was, he was an old whitey!