I bought an 18mth old Pomchi -who is, I have discovered, Head of Foodstuffs & Chews Quality Control. He either hates it or loves it, and then he loves it and then hates it or hates it, then 5 seconds later it's the best thing ever discovered. Often multiple times a day. I am spending a fortune on things he loves/hates/loves again but this Yak chew was a winner-consistently over a week. As yak chews are seriously hard I was worried the small size (Approx an inch wide and half an inch deep) would prove too difficult for a 3.5kg toy breed as his teeth and jaw size really are weeny, but this size-as shown in photo- has not proved to be too difficult nor too hard for him at all. He is a determined chewer and he really gets into this chew in all manner of positions so it is definitely working his intelligent little brain too. His stomach has shown no upset, and he actively seeks this chew out now as he has broken the initial straight/square edge and has clearly now realised if he keeps going and keeps licking it it turns this hard yellow boring stick thing into The Best Cheese Ever and gets easier to gnaw the more he gnaws it! I shall be sticking to this shop/brand as he is VERY difficult to please and other attempted yak chews have resulted in them being completely ignored and given away to my neighbours dogs.