Do they slobber, snore, shed, smell or pass gas?
Most Mastiffs will only drool when (1) they have just had a drink of water, (2) are extremely agitated or fearful, or (3) when watching you eat something they think will taste good (and that will be everything you eat!). Mastiffs with less flews tend to drool less. The experienced Mastiff owner keeps “slobber towels” handy, and wipes faces after they drink and when they need it. I feed and water my dogs outside to decrease the mess inside. It also helps keep down the “slingers” of drool that may occur while they are eating and drinking. If you are going to keep their water outside, then close the lids on the toilets. To a Mastiff, a toilet is an all you can drink bar. Just remember, “Spit happens” when you own a Mastiff.