While on the owner's property, a dangerous dog shall be securely confined indoors or in a securely enclosed and locked pen or structure, suitable to prevent the entry of young children and designed to prevent the animal from escaping. If such pen or structure has no bottom secured to the sides, the sides must be embedded into the ground no less than one foot, and shall also provide protection from the elements for the dog. (Ord. 912, § 2, 1988.)