Nylabone Dura Chew Chicken Flavor (Souper) is safe for dogs of all sizes and breeds. Dogs gradually grind it away, rather than breaking off chunks. The Dura Chew does not support growth of micro-organisms and can be sterilized by boiling. Chewing helps alleviate stress and benefits teeth and gums. Made of safe nylon, suitable for very aggressive chewing dogs. Chicken Flavored Nylabone Durable Bones have flavor particles baked-in for extra appeal ? the pickiest dogs go for them!