While clipping your dog's hair is not necessary, trimming the fur around your dog's anus and genitals, as well as the face and paws, is essential for health reasons, according to the Pup Dog Training website. These areas tend to accumulate the most dirt, including urine and fecal matter, and can be sites of possible infection. Teaching yourself how to trim the long hairs on your male dog's sensitive prepuce (the skin covering his penis) keeps him cleaner, and can save you money on professional grooming.
Place a towel a little larger than your dog on a table or the ground, depending on the size of your dog.
Place your male dog on his side on the towel with his belly facing you and his back legs open so you can see his prepuce. You may need a helper to hold your dog and keep him still during the trimming.
Place one hand directly in front of the prepuce, and, holding the clippers or grooming scissors with the other, begin trimming the hair of the prepuce without touching the skin.
Trim just enough of the hair to be esthetically pleasing. Cutting off all the hair can cause razor burn and/or skin irritations that can lead to skin infections.