peeing/humping

Question
I have 1-1/2 yr old Norwich Terrier, she has taken some time to get potty trained. She does great at home, but when we go to families homes with other dogs, she will pee all over on me the couch, floor.  Usually it is triggered by a more dominant dog.  She has no fear and even when the other dog is showing his teeth and warning her she doesn't back down and gets low to the floor and starts to pee.  She actually jumped up on my lap the same day when no dogs were around her and she peed on my lap.  When we got her she was the only puppy along with apprx 10 adult dogs. She had to fight for everything in the pack. Food, attn,etc.  We have a 5 yr old JRT and she trys to get all the attn when at home but doesn't pee all over.  The other thing she does is sometimes when we hold her up in our arms she starts humping us I don't no if it's the way we hold her?  She is spayed.  Any suggestions?

Answer
However much good spaying does, it is no cure all.  Urination can either be a sign of submission or a challenge.  If she saw you as a strong leader, she might not have to urinate to cope with another dog.  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