Dog does not have a weight issue; she comes from a Viking blood line. Dog will survive the apocalypse. You probably will not.
Dog finds very many things to be stimulating. Unfortunately, human antics do not fall within the aforementioned category. Her limited involvement with the house Staff allows for a myriad of tasks that further her own personal development as a ruler.
With great power comes great responsibility and with great beauty come great power. So much power, in fact, that Dog can order her Humans to buy her a stylish rain jacket and then pretend not to like it. Observe: