I had never done that before until today. I had always just figured that since I had kinda felt around down there and didn't feel anything funny, therefore it didn't need to be cleaned. I always spray water up there and I figured that probably took care of whatever issue there might be, right?
Today, I was giving Lacey a bath and I had noticed that she has been really rubbing her tail. So I decided to do a little exploratory feeling with soap. Well, I found some of the biggest chunks of yuck up there. It was basically like she had a freakin' ping-pong ball between her teats.
I also discovered that she has quite the colony of melanomas down there too. That's actually what the smegma (that's what it's called, right?) was collecting on. She has a marble sized one right in between her teats and quite a few smaller ones all around.
But yeah, now I know more about my mare than I did, and hopefully someone else can learn from that too. :)
So, remember to clean the teats of your girls! They may be less obvious but they get dirty too!