There are few reasons for.
My dog is licking his rear end a lot, is this a sign of anal gland problems or something else? The answer is that many things could cause your dog to lick excessively in this area, but irritation from the anal glands is very likely. Another reason why anal gland problems could.
There are few reasons for rear end irritation and licking. The most common is due to fullness of the anal glands located in the wall of the rectum.
There are glands on either side of your dog’s rectum that produce a very pungent fluid. Dogs drag their rears along the ground because of itching or pain around the anal area. The anal glands normally release a very pungent discharge that is even stronger than the smell of feces.
If you notice your pet scooting across the floor on its bottom or constantly licking its rear end then it's an indication that she may be suffering.