Our dog, 2 years old female Chihuahua, is potty trained and 99% of time, she goes out to the patio through a pet door where potty papers are always. The other day we found her urinate in our bed! First time! Hopefully last time. We thought dogs never pee where they sleep or eat. She even sleeps with us in the bed often times. She also did that on the rug several times. She knows she is not supposed to do that, so she sometimes immediately goes to her own bed and hide in it. We don't understand why she does that when she knows where she is supposed to do her business and we get angry with her after she urinates in the house. What should we do to stop this? Any suggestion would be appreciated.

It could be that at 2 years old, she feels she is a big girl now and is challenging you for pack status. 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 Raising Your Dog with the Monks of New Skete For more on being top dog, see Establishing and Keeping Alpha Position