Certainly a diet high in roughage will aid compression of anal sacs. Many dogs when excited will spontaneously express their anal sacs, considered normal. And there are commercial products to aid in covering or reducing the anal sac odor.
The most efficient product available to remove the odor is simple ethanol, methanol or isopropyl alcohol. Careful when using any alcohol (I would suggest a dilution of isopropyl on a gauze pad) simply because it can irritate any sensitive skin. Blot the area lightly and gently.
If there is an underlying allergy problem or chronic source of skin irritation, then one usually finds excessive anal sac discharge.
Dr. Van Lienden
Dr. Raymond Van Lienden DVM
The Animal Clinic of Clifton
12702 Chapel Road, Clifton
Virginia, U.S.A. 20124