Nylabone DuraChew® Bone is designed for powerful chewers. Bristles raised during chewing help clean teeth and control plaque and tartar build-up. Nylabones are not digestible. Replace if your dog should break off any pieces larger than 1/4 inch. Nylabones may be washed with soap and water. Do not place in dishwasher or microwave. Nylabone DuraChew® Bone may be washed in warm water with nontoxic detergent. Rinse well before returning to dog. Do not place in dishwasher or microwave.