Call me stupid, but I've done a search on this and all that comes up is, yeah, I didn't know what the smell was, but I expressed his anal glands, or you might need to express the anal glands.
What does this acutally involve and how do you know you should do it? I have NEVER heard of this, but I've only been a dog owner for about four years. :p Does it happen that it needs to be done in certain breeds more than others? Thanks for informing the uninformed :D