Are you talking about anal sacs? Any dog, male or female, may need these expressed from time to time. The sacs fill with fluid, and theoretically the fluid is expressed with the dog's stool, but for some dogs this doesn't happen correctly.

If the anal sacs fill with fluid it IS necessary to express them, because the sacs can become impacted and infected. It stinks, it's painful for the dog, and it can become quite serious.

Fortunately, I've never had to do this with Jasper. My mom's dog, Star (female) does need her anal sacs expressed periodically. We can tell when it's time because she starts licking at them and scooting on the floor because they are full enough to be uncomfortable. Of course, I try to express them before it reaches that point, but since I don't live there I sometimes don't think of it until someone tells me she needs it done.