Pug-Zu

while it won't be a 'large' dog, I'd guess it would get over 10 lbs.  Pugs are pretty stocky little dogs. 

do you think it will be small enough to litter box train?

Neither pugs nor shih tzus should be under 10 pounds at adulthood, so I would suspect that puppy is going to be larger.

Secondly... litter box training doesn't generally work perfectly with dogs. Unlike cats, there's no instinct to bury it, so to prevent odors, you must clean the litter box each and every time it's used. In general, it's much more sanitary and healthy to take your dog outdoors on a leash. Even small dogs need walks.

i wasnt implying that i would not take her for walks, but i dont think she needs to go for a walk every time she has to potty.  i dont mind cleaning the litter box after her.  i just dont know if she will fit in it when shes grown []

Oh well I guess it doesnt matter that much.  I wouldnt mind taking her outside to potty either.  i would post pictures of her if someone can tell me how

ORIGINAL: Pwca

Neither pugs nor shih tzus should be under 10 pounds at adulthood, so I would suspect that puppy is going to be larger.

Secondly... litter box training doesn't generally work perfectly with dogs. Unlike cats, there's no instinct to bury it, so to prevent odors, you must clean the litter box each and every time it's used. In general, it's much more sanitary and healthy to take your dog outdoors on a leash. Even small dogs need walks.

well the standard for a shih tzu is 9-15lbs according to the akc.  the op may have a small mix but i would not think it would be under 10lbs.

as far as litterbox training it is much easier than people think.  i trained our chi to a litterbox as did my friend her own two.  i am now training my granddaughter's new pup to the litterbox as well.  my only concern with a larger dog would be to find a litterbox that would accomadate them.  i use the booda clean step and i am thrilled that if i am gone longer than anticipated not to have to worry about coming home to an accident.  as far as cleaning after every use that is not true... we have to clean once every day or two.  there is no smell but you do have to use a clumping litter, unlike what is stated when doing research on litter training a dog.

ORIGINAL: Lilea

i wasnt implying that i would not take her for walks, but i dont think she needs to go for a walk every time she has to potty.  i dont mind cleaning the litter box after her.  i just dont know if she will fit in it when shes grown []

 
i would be concerned with the size of the litterbox you will need.   my chi is litterbox trained.  when i started her i worked very hard at following all the do's and don't's for training a dog.  what i did find is that if you do not use a scoopable, clumping litter the dog will never seem to use the box more than once.  i use the booda clean step at my house and i really like it but than zoey only weighs 4lbs.
[linkhttp://www.pet-dog-cat-supply-store.com/shop/booda-dome.php]http://www.pet-dog-cat-supply-store.com/shop/booda-dome.php[/link]

My pup is 15 lbs and I'm pretty sure I saw some litter boxes at petsmart that would fit her with room to spare. I don't use a litterbox for her, though. I was actually looking for a cheap one for my nearly 10lb rabbit, lol.

Harley is about 13 lbs. 
 
What is it you are looking for in a dog?

Small breeds don't grow a whole lot after six months so unless you need her to to be under 10 pounds for some other reason I'd say she won't be much more than 10 (but weigh her now for yourself. People are notoriously bad at giving correct weights. That may be an old weight.)
 
My Jack is 9 lbs, 10 ounces. He uses a 14 x 17 litter box and never has an accident. (He's also neutered so he doesn't lift a leg.)  There are litter boxes bigger than this if you really need one. Purina SecondNature makes a bigger box. I woulnd't use their litter though. It's expensive and no better than Yesterday's news which is cheaper. You can also use Feline Pine or Feline fresh. Clay litters are very dangerous for dogs. Aside from the fact that when they are being trained to it they will get their paws, noses and eyes full of it the dust from it is very bad for them.
 
Don't expect him to use it without good training for it. One way to start training is to put him in a pen at night with a litter box in it. I use a 4 ft. square pen with a crate (door open) inside it. This doesn't give them a whole lot of room to pee/poop on the floor and get away from it.  Beware, my pups cry to get out of the pen because they don't want to use the litter box in it if they have a choice. Given no choice they will use it.  You have to watch him when he's out of the pen just as carefully as you would if he were being outdoor trained.  Make sure you have a litter box outside of the pen because they will almost never go back into the pen - even if they can get in - to use the box.
 
Your success may depend on how he's been trained so far. If he's already good at going outside there's a good chance he won't want to use the box.

Firestorm, what I want in a dog is small and friendly.  that about sums it up.  And I was hoping to be able to train her to use the litter box.  The 10 pounds thing is my rule because of the litter box thing, she just has to be under 20 pounds for the apartment.  This little girl I am getting is trained to sleep in her unlocked kennel at night in the bathroom.  She does go potty outside but is not completely trained.  She also uses puppy papers in case she has to go during the night when shes in the bathroom.  I can leave a litter box in the bathroom with her at night.  Will she know shes supposed to use it or do I need to show her somehow?  Put some of her poop in it?
I have a cat already, do you think I would be able to get them to share a litter box?
I am getting a very good deal, $100 for her and all of her things.
Going to pick her up today

i am going to say that i would not have the dog and cat share a box.  also you will need to show your little girl how to use it.  you can start out putting puppy pads in the box and than slowly adding litter.  as stated i would only use clumping cat litter.  as far as the post talking about the dangers...if the litter is not dangerous for a cat how can it be dangerous for a dog?  just my thought... i tried old news and had no luck with any of the litters till going to a clumping cat litter.  it is not like the puppy is going to stay in the litterbox and play... they go in do their business and come out. 

OK, thank you everyone, you have given me great advice

well i for one will anxiously be awaiting pictures of your new little girl.  have you named her yet or is she pre-named?
happy holidays