I was skeptical about this since my 1 y/o 10 lb poochon is such a picky eater, but I went with the small size bag for her teeth health. I am impressed how she enjoys eating such gigantic nugget, far more than her usual kibble (Hills little paws chicken puppy, smallest kibble out there). My dog is not an agressive chewer, especially on the food side, she doesn't enjoy treats like rawhide or porkhide, but she seems having no problem chopping down this hard nugget. It is hard, but more airy and crunch inside than her usual kibble, so less dense.She rarely eats breakfast when I give her usual kibble since she has less appetite in the morning. When I mix this into small kibbles, she only eats this giant kibble. So I ended up giving her this (6 nuggets) for breakfast, which she devours slowly but surely(Amazing!), and give usual kibble in the evening.My dog hasn't had teeth problem yet, and I hope this kibble helps to prevent one! I will keep buying this as long as my dog keeps liking it!Update: Feb 2020My now 11lb dog finished 4lb bag in 3 months. She still likes it, and big nuggets in the morning and small kibbles + wet dog food in the evening works fine for her. I do notice her breath is fresh, except for the morning breath. She is now 15 months old, so still too early to tell, but the vet said her oral health is very good for now. I also notice there is no plaque building up. I am subscribing this now, and recommending around other dog owners.As for the reviews that complains about the size being too big, I believe it's up to your dog's preference, rather than the size. I had 5lb yorkie came over, and she destroyed 5 nuggets in no time, loving it. I guess this is worth trying!2nd update March 2021:I have kept my dog's diet as I described above over 1 year now, and my dog is 2 and a half year old, who won't allow me brushing her teeth at all. She doesn't like any dental chews out there, so basically this kibble is the only defender for her oral health. That and her lo.