I have a two year old little boy named Maxwell. He currently weighs 3 lbs but in the past has weighed almost 4 lbs. In the last couple of months he has begun to lose weight. He is a ferocious eater. Also, recently he has been losing his balance. When he walks it seems that his back end drifts to one side and at times he almost falls over. I have taken him to the vet and they have done two seperate extensive blood workups but they can not find anything wrong. If anyone could help me I would be so greatful. I do not know what else to do.