He is probably dehydrated and malnourished from not eating for a while. I recommend going out and buying some UNFLAVORED PEDIALYTE. Prepare a bath with the Pedialyte at a 10 to 1 ratio. So for every 10 ounces of de-de-chlorinated water add 1 ounce of unflavored Pedialyte. Make sure the water is Luke warm and no deeper than up to his chin. Soak for 20 minutes. This will help hydrate him. Perform this bath daily for at least a week.