Hello everyone i think my puppy is severely underweight. The vet didnt think the age was correct when i showed him the papers so i contacted the breeder. He told me the age was correct and that this was the mothers last litter and she nursed them poorly. So by going off the breeder he's 17 weeks old and weighs 15lbs. I feed him half a cup 3 times a day but now im wondering if i should be feeding him more as he's less than half of what he should be according to what i read online. I saw his father and he was huge, his mother looked normal the other puppies around him didnt look any bigger so i dont think he was a runt. Im lost, any help is appreciated.