I have a sixteen week old bitch who weighs about 10.5lbs. One vet says she if fine and will be a big dog. Another vet from the same practice said she looks a bit on the thin side. Bella also has dihorrea at the moment, which she has had for about two weeks and we are awaiting results of the test from the vets. Is this a normal weight for a dog this old. Her mum and dad are both big dogs. The breeder said her mum went through the same stage where she went tall and skinny and then filled out. Is this normal? I can slightly see some of her ribs. She was quite fat as a eight week old pup when we got her. Any advice would be extremely greatful.