I have a 5 month old Boxer girl who is eating pedigree puppy food mixed with pedigree canned puppy food. She is commpletely uninterested in her food, she would rather eat my 2 year old's food which is just pedigree kibble. Is five months to soon to switch her to dog kibble mixed with canned puppy food? She likes the canned puppy not the puppy kibble. Any ideas?