Does the mother have a sufficient milk supply? Did you have her checked by a vet before, during and after the birth of the babies, was she on extra vitamins, food suppliments? To be honest, after the first one died, I would have been getting it checked and not leaving it till they have died one by one.
thanks, ausgirl. But i must say i've done all the things you refered to. we gave them good dog food, milk. and it cost me much to take him to the vets'. but he was just coming back home when he died! we really dont know why.