Since my dogs hate water, we throw water on them. Even in the house! Depending on the dogs involved I can usually pull them apart. Taggert almost always seems to be one of the ones involved. Usually it is over food or rawhide. If I see Taggert starting to get possessive (hair raises on his back and he starts a growl), I can usually tell him to knock it off. We know feed them in their crates but that is more because Snoopy will eat everyones if he gets a chance.