I’m sorry your pup is struggling 🙁 If I were in your shoes, I would try fresh fruits because they usually don’t have any fat, plenty soft fruits options and low in kcal. I would also make sure that the total calories coming from these treats to be less than 10% of total caloric needs/day. I like blueberries for tiny pups. I have a 7 lb. chi x papillon, and she can eat about 50 blueberries, which is about 40 kcal.