This "doggy" smell is the very reason I installed a central vacuum system in my house! I just could not stand the smell that came from of my machines every time we vacuumed, even my Miele's with their sealed HEPA filtation.
I had a nearly 100 pound German Shepard mix for 11 years, she had the body shape and coloring of a shepard but didnt have the very long hair. In any Kirby that I owned while the dog was alive, I would launder the outer bag once to twice a year. When I had a G4 and then later with my Diamond Edition, I stuck the bag, emptor and all in our TL Fisher&Paykel on the gentle cycle with a small amount of Tide, and then let them air dry. Since we only have a cat now, I use the Kirbys strictly for the few carpets we have and the central vac for everything else, now I only need to wash it once a year, if that. This past summer I washed the Diamond Edition and Ultimate G bags with emptors attached and a towel or two in our Bosch FL on the gentle cycle with a little Tide (a little HE detergent goes a long way), and then let them air dry. This way saved me the trouble of detaching the emptor and fill tube and from washing them out by hand and allows me to do it all in one shot in the washer. Both bags came out looking great, no fading or damage at all, and no "pet smell". I've tried Electrolux Clean Sweep chips in the Diamond just to mask any dust smell, but I only use a 1/4 to 1/2 of a packet or the scent is just too overpowering. The only way to really get rid of the dog smell and not just mask it, is to launder the outer bag.
Best of Luck!
PS. Now that Im thinking about it, I beleive I put each bag inside a large old pillow case just to make sure they didnt get scratched from hitting the drum when tumbling inside the washer
