Fixed Male Dog Peeing on Women

Question
I have a well-behaved, gentle, submissive rottweiler (therapy dog) who has started a new habit of peeing on women at the dog park. A different woman each time. He marks everything else too so I don't know why he is doing this. He is so quick it is hard to catch him in the act. Every one loves him at the park because he is so obedient but this will soon change I'm sure if this behaviour keeps up. Please help explain why he is doing this. Thank you!

Answer
Neutering a male dog usually improves its behavior, sometimes requiring little more to eliminate marking and other undesirable behaviors.  In many cases, the owner still needs to give it good leadership.  A dog can obey commands without acknowledging the owner as its leader.  

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