dogs do shed ,but not always. do bresh him regularly. he might be going low on vitamins...see to it that he is geting the protiens and vitamans required daily. there r many coat improvement syrups... contact ur vet for it.
if the shed is in a particular area and he is getting bald...than it might be a skin infection...........in that case the treatment should be done for the skin infection and not for shedding.