How do you take care of an english mastiff puppy? Answered By: Orlando Friesen. Date created: Fri, Apr 2, 2021 3:01 AM. Giant breed dogs, including Mastiffs , need to grow slowly and the adult dog food formulas have the correct protein balance (approximately 21% - 23%) required by the puppies. When you first pick up your puppy , it should be fed three (3-4) times a day, approximately ? to 1 cup per feeding. Answered By: Ottilie Reichert. Date created: Sat, Apr 3, 2021 1:02 AM. Where Do You ...