Expert: Anne Springer, B.S., Dip., CAPCT - 4/8/2008

Question
i have 3 dogs , 2 males 1 female spayed, the one dog nutered.yorkie poodle female and shih zuh, the shih tzu has always been a placid gog of wich his age is20 monthes. but suddenly i was getting him to come to his bed when he growled and bit me . not breaking skin or blood. slso hes peeing everywhere always have. do i gethim nutered woyuld it help

Answer
Neutering often does help with urine-marking and sometimes with aggressive behavior, too.  I think it would be a good idea to take this dog to a good positive reinforcement class where you can learn to train him to follow your directions. This link has some useful information.
http://www.hilltopanimalhospital.com/deferential%20behavior.htm
Dogs that don't respect the human in the household often exhibit this kind of aggression, and it's important for you to get help in training the dog to accept that you are in control (without using any heavy handed punishments, which often makes things worse).  NILIF, or "nothing in life is free" can help you, but you must teach your dog a few simple behaviors, like sit or down.  Then, you can use those behaviors to insist that your dog "ask permission" or "work" for what he wants.
Any time a dog has broken skin, my advice is to consult with a behavior pro in your area.  You can find one at the IAABC, APDT, or Animal Behavior Society web page.