A system (100) and method (900) of training or modifying the behavior of pets and, in particular, dogs is disclosed and could include using scratch-resistant protector (104, 200, 300, 400, 500, 600, 700, 800) having adhesive (202, 402, 602, 802), additive (302, 404, 502, 604, 702, 704, 804, 806), or both to protect the integrity of door (102). Adhesive (202, 402, 602, 802) could generally provide a securing or coupling relationship between door (102) and protector (104, 200, 300, 400, 500, 600, 700, 800), while additive (302, 404, 502, 604, 702, 704, 804, 806) could provide a material that canines find unpleasant to smell, taste, touch, or scratch. In one embodiment, additive (302, 404, 502, 604, 702, 704, 804, 806) could include an additive that may be reapplied if it wears off or otherwise diminishes in strength, quantity, quality, or overall effectiveness.