it was great of you to save him. he was totally on a wrong diet and you are doing much better by him now.
My yorkie is now 4.5lbs and on a raw diet. However she was on kibble when she was a puppy and she never got 1 cup of food. that was way too much. She mostly ate 1/2 cup of food a day and usually didn't eat all of it. so if your little guy is getting 1 cup a day sometimes and 13 weeks i think he's eating too much. Ask your vet to be sure.
__________________ Kellie  and  Morgan |