My 8 month Lab/Pit is starting to poop in her crate after months of not doing that

Question
Hello, my 8 month old spayed black lab/pit mix has decided this week that she's going to poopoo in the house and/or her crate as she pleases.  Sometimes twice a day.  We walked her up to 3 or 4 times a day.  We live right next to a dog park in SF so she gets lots of running and attention.  We had this problem before when she was real young, but it's been months since she's been doing this.  Sometimes after running her around for like an hour or so, we'll head back home and she'll poop in the house when we get home.  I have no idea why this is happening all of a sudden... do you?

Answer
Most behavior problems need to start with a vet visit for a checkup, explaining the problem.  Otherwise, even spay/neutered dogs challenge their owners for leadership as they mature.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm