Our shih tzu is 10 lbs - 12 lbs. so similar in size and he is 10 months old. He eats breakfast at 5:30 am (I'm up so I feed all the dogs and take them out). First we go out and he pees & poops, we come in, I put him in his playpen and feed him, then I go off to do whatever...My daughter gets up act 6'15 gets ready for work and takes him out at 6:45 he pees, occasionally but not often he will poo. He then has full range of her section of the house. He is then fine till about noon and he goes out back plays and pees more. (he does pee several times when taken out, unlike my other dogs who go once and its over with. He then eats dinner at 4 pm, and my daughter takes him out at 5 ish when she gets home, He pees & poops. He then gets a snack like a chicken chew jerky. Thats it till 8-8:30 he will go out 1x more and pee. There are times he does a 3rd poo but we can kinda guess if he went a very small amount earlier he may have another, like he didn't clear himself out the first time.