Pooping pellets generally means there is an issue with nutrition/diet. My dog poops pellets if the dog food is too high in protein or if she is not getting enough water. Try a wet food or a food with different protein contents. You can also add a little pumpkin (not pie filling, real pumpkin) to food and that sometimes helps.
My Dog Is Pooping Little Rocks, But Only Has Pellet Sized Bowel Movements. It Obviously Hurts Him When He 'Goes' But We Can't Afford Surgery. What Is Going To Happen To Him?
My retriever just started pooping small pellets 2-3 times a day one pellet per time. Hills WD diet is very recent. Does he have a problem?
Try feed it different food and see what happens... Maybe its the food he is eating.