house breaking

Question
Our family includes two Shih Tzu dogs. The female is 5 and the male (her offspring) is almost 3. It took a very long time to housebreak our female, but I would say by 18 months or so she was pretty well done. Our male is the most happy-go-lucky dog you have ever met, oozing with sweetness, and seems not to have a dominant bone in his body. The female is also very sweet, albeit protective of him. At about 22 months of age I thought the male finally had the housebreaking thing down (with a little help from new hardwood floors and ditching the ruined carpet). Recently he started marking around the house, on things like my bathrobe hanging in the bathroom, rugs around the toilet, a winter scarf hanging over a chair, the ironing board, a suitcase, fresh laundry hanging from a door handle. I adore these dogs, they couldn't be any sweeter, but I am pretty frustrated with the marking. I have had dogs all my life and have kennel trained each one from a puppy with tremendous success. The only thing I did differently with these two is that I kept them kenneled longer (well over a year)because they were not trusted without someone in the house. Now that this male is 3, is there anything I can do to fix this problem?

Answer
Neutering?? If he is not neutered, DO IT.  Testosterone driven behavior such as marking won't respond automatically to neutering at this dog's age, BUT it will diminish over time while you manage the problem.

This isn't a house training issue, per se, but it can become one.  Go back to Square One with his house training. Take him out and reward/praise every elimination.  Indoors, you can do one of two things.  Either put a very long, very lightweight house leash on him so you can observe him (and he can't get away from you to mark things) and/or use a belly band.  These devices can be purchased on the internet and they work because they make it impossible for the dog to eliminate without retaining the results against his body.  After two or three attempts, he'll soon learn he doesn't like the results.  I'd suggest doing both in conjunction with one another.

Additionally, help make this dog feel more secure about your leadership abilities by using positive reinforcement to teach him one solid 'sit' behavior (but use a unique word).  Once he's obtained a 100% solid response to this command, make him 'sit' for everything for about three months: being fed, being petted, played with, taken in/out, etc.  This will psychologically promote you, enhance his problem solving skills, make him more emotionally secure and give him the clear signal that he does NOT need to mark your "territory".