I have a 4 month old, female, black lab/australian shepherd mix. I bought her when she was 3 months old. During that time I have continued to feed her what I was told she was already eating which is Purina Pro Plan Sport which I did research on and many people with labs have had great success with. I asked my vet about this and she said it was fine and that this food can also be given to them from pup to adult. However, I did notice when I bought her that she looked a little overweight. She was 22 lbs at 3 months and is now 34 lbs at 4 months. I?m not too sure if that?s normal, but I?m assuming it depends on the individual pup (some are just larger than others). I do know that she looked a little overweight to me. I assumed that perhaps they were feeding too much. I did some research and decided on 1 3/4 cups in the morning and 1 3/4 cups in the evening. When I went to her recent vet appointment to get her shots a different vet had to see her, because the other was not working that day. While this vet seemed way more attentive (I believe his dad owns the clinic), he told me that the sport plan was not suitable for pups and that it should only really be given to the most active of dogs. He recommended that I switch to Purina Pro Plan Focus chicken and rice formula for puppies and switch to an adult food at around 8 months. I?m completely on board with that, because I also read that the sport 30/20 has a higher fat content (although the solution I was thinking was just switching her to the Sport 26/16, but I was fine with the focus). My concern though is that he also said for me to only feed her 1 5/8 cups per day and to just split that in half to feed in the morning and evening. Do you feel that this is not enough? She does seem to be quite hungry still after. She?s smart and let?s me know what she wants. She?ll bring me her water bowl when she?s thirsty and drinks all of her water. She?ll now go and stare at her food bag that?s up on the shelf. I don?t want her to be hungry all the time, but if the second vet was correct then perhaps she is just one of those pups that can eat until sick. What do you all think?