Try giving the pet some baby non-flavored pediolyte.let it drink all it wants.Remove drinking water,and try boiling some chicken,cut into small pieces,put in blender with small amount of water and puree it.Most dogs will eat this when nothing else.If your pet won't eat,you must force feed it with a syringe.Give your pet a dab of plain honey or Karo syrup on its tongue to elevate its sugar level,which is probably low from not eating.If your pet hasn't been dewormed lately ,you may need to deworm it with a safe wormer like Panacur,you can purchase this at any vet clinic and it is given by weight and three days in a row.This dog will get weaker as time passes without food,so force feed it if it won't eat.