My puppy is about 6 months old, she has been with me for 3 months and suddenly she has stopped eating her food. She will eat but not eating nearly enough for a growing puppy. We have tried adding chicken and she will eat that but it get expensive super fast and adds extra proteins making it too much for her to be eating. She has an extremely sensitive stomach, she will still eat her treats and anything she can find on the floor. People say dogs can't get bored of their food but I really think she is just bored of her food, please help

Puppies can be like children who won't eat their veggies for dinner if they know after they are getting ice cream. Try not giving her any snacks or people food for a couple of days, my bet is her bowl will be empty after 18 to 36 hours.

If this is the case, then try only allowing treats and other foods once a day or less, but on a schedule or as training incentives during training time.

Sometimes adding a little water to soften hard food can help if it is a texture thing

You can try a little fat or broth to make it smell like people food, to trick them if you're still having trouble. To much is no good either though.