Dogs skin health

my dog frequently gets this foul smelling discharge around her neck to the point I have decided she cannot wear a collar unles it is a choker collar for out in public. Is this a regular occurance for her breed because she is a long haired dog? She also gets alot of dry, scally patches down her back to her rump and tail. What can I do to prevent this?

My first guess is that there is some sort of lesion in her neck area that you aren't seeing because your dog has so much hair.
   
Otherwise, your dog's neck skin would simply be spontaneously excretig the foul smelling discharge, which is unlikely. There has to be a root cause.
   
Because your dog also appears to have another skin issue, you are best off springing for a trip to the vet to get to the bottom of this problem.