Whether or not a rescue Cairn is housebroken depends on the individual situation. All rescue Cairns MUST HAVE a crate, and the owners are urged to train the Cairn as one would a puppy for the first several months regardless of whether the Cairn was housebroken before or not. Good beginnings make for happy endings, and it is better to reinforce the desired behavior from the start rather than try to backtrack and retrain later. Cairns are a smart breed and will learn the rules if the owner takes the time to properly train.