Ensuring you have the correct size is vital. Always try the muzzle on your dog to ensure the right fit. The nylon muzzle should fit snugly, but you should be able to insert a finger between the muzzle and your dog's skin. If your dog is prone to biting, always ensure someone is there to assist you to stay safe when putting on the muzzle. Praise your dog and reward him while the muzzle is on to create positive associations and prevent your dog from starting to avoid it.