I suggest the small size over the large size (even if you have a large dog). I bought both sizes and it’s the small size the dogs like best (including my Doberman). This is a great toy for puppies, high energy dogs, and fast eaters. It causes mental stimulation and the dogs always take the best nap afterwards. Definitely a must have if you have dogs! LTKFindsUnder50 LTKGiftGuide