The Dog Casino by Nina Ottosson is a smarter option for pet parents and dog trainers looking to engage and excite their dog through training. Opposed to thr typical treat dispensing toys, the Dog Casino is filled with obstacles and new features that keeps dogs playing and happily learning. This game has built in pieces that don't come out when your dog is playing with it. Unique to the Nina Ottosson Dog Casino is the locking bone pieces. If your dog is good at solving puzzles, introduce them to a new challenge by simply twisting the bones on top to lock the drawers. You can mix some raw/wet/dry food with water and pour into the hollows, put in the freezer to set and let it set. Perfect for the energetic dog, hot weather or just extended fun. Easy to wash – simply remove the left over treats/kibble and hand wash in some warm soapy water, rinse and dry.