I came to realise that the breeder of our puppy used the puppy current weight rather than the expected adult weight when working out food requirements.
I was very careful to check 100% that puppy came from home breeder with prior experience of puppies (not first time due to Covid) and all health tests were carried out. However this major error on her part came to light when I collected puppy and she told me the amount to feed. A few days later I checked the packet myself and realised the error. So damage done already, I decided to feed correct amount and everything would be fine physically she would be ok. She was otherwise healthy and vet checked.
We have had puppy a number of weeks now and I am beginning to worry about the pschological effects of this under feeding. She seems permanently hungry and looking for food even though I am now probably giving her more than she needs. I am worried this could develop in to resource guarding. She eats super fast almost choking on her food and does look around nervously. No growling at us though.
Not really sure what to do. I am first time puppy owner and inexperienced in handling any complex issues. Feeling quite stressed about it.