Some dog breeds, like the Pomeranian, have long fur around their rear ends and their legs. When the dog defecates, feces can become stuck to the fur, which in turn leads to unattractive clumping and a foul odor. Shaving and trimming the area around a puppy's hind end prevents this problem and leads to a more groomed look. While a professional groomer should take care of any dog destined for the show ring, it is entirely possible to shave a puppy's butt on your own.
How to Shave a Puppy's Butt
Hold the puppy underneath your arm, on its back. Have an assistant help you if necessary.
Hold the tail down with one hand to keep it out of the way.
Trim the hair around the puppy's anus using a pair of hair-cutting scissors. Always cut away from the skin; never point the scissors towards the puppy.
Brush away any loose hair with your hand.
Put a low attachment on your electric shavers, one that clips the hair to ¼ of an inch, for example. Use 1/2-inch or 3/4-inch attachments to clip the dog's legs, if you prefer. You can always go back and clip away more hair, but not vice versa.
Shave the hair away from the rear end and down the dog's legs, using a light touch.