No. Kong Toys are a simple and fuss-free way of providing your dog with mental and physical stimulation. Filling the toy with treats and munchies is a smooth walk in the park. It is, however, important to seal the toy with peanut butter or Kong Easy Treat to prevent the treats from falling off. Also, Kong Dog Toys are extremely easy to clean, and can even be used in the top rack of the dishwasher.