How Much Should A Shih Tzu Weigh?

It will depend on your dog and their own personal build as to what weight is right for them. The ideal weight is 9 to 16 pounds for a Shih-Tzu and it's this weight range for show (the hair length for show is too difficult for most to keep up on their pet BTW). Pups bred to be smaller than that often have additional health issues (like liver shunts) that contribute to their size or just from a lot of irresponsible breeding to try and make them smaller and breeding dog's below recommended weight. Here's the link to the standard and the breed parent club where you can find lots of information about them. If you mouse over the links on the left side you get a whole list of more information on most of them.

http://americanshihtzuclub.org/breed_standard www.americanshihtzuclub.org

My shih tzu is 4 months old poppy weighs 10lb is she over weight

An adult should weigh approx. 8-10 lbs.

Shih-tzus vary in weight from 3lbs to 16lbs, depending on genetics and what they are fed.