I waited until my puppy was 6 months old to start giving him Greenies 'cause that's what the package says. I have several friends who give their dogs them and they all love them. At first my dog did too - acted like it was a special treat and went off and devoured it. After about a week though he lost interest, he'd take it and then go off and leave it on the floor and doesn't even touch it. Has anyone else had this experience? Should I be worried or getting another type of thing for his teeth? He's just a puppy so who knows his taste buds might change but I do want to do something for his teeth. I tried brushing them but that doesn't seem to work very well. He clamps down and refuses to let me get near him with the toothbrush.