I have to say that I am in love with the idea of Greenies Dental Chews, but they just didn't work for my dog (a 5 year old yorkie). However, I will say that my dog is starting to develop stage 1 periodontal disease. We weren't expecting a miracle product by any means, but something to at least help control my dog's bad breath and maintain the current health of his teeth. We tried Greenies Lite Canine Dental chews to develop a daily dental routine for our dog that wouldn't cause him to gain weight as a result. Although my dog loved the taste of these, he devoured them so quickly that I don't feel like he had a chance to allow the product to work. They fell apart so easily. My dog's breath would smell neutral just after eating it, but his bad breath would return almost immediately. In my opinion, this product is too expensive to justify buying when I don't think it really did the job. At the end of the day, I feel like this product would be a good alternative to the occasional treat, but as a vet would recommend, it shouldn't replace brushing your dog's teeth. Side Effects No side effects noted.