Hi @annelisle Great question and I hope we can help you and your cousin. (Is this the pup, cute!)

House training or 'Potty' training a puppy or untrained dog is one of the first challenges a new owner has. While some breeds have reputations for being somewhat more difficult to house train, with patience, praise and consistency, all dogs can eventually learn that outside is the place to 'do their business'.

Especially with a puppy, a schedule is the most important part of the training plan. Monitoring food and water intake, and taking scheduled regular 'potty' breaks based on your puppy's age and size (please consult your vet) will help to instill the right pattern of behavior - 'going' outside.

Another helpful hint is to provide an enclosed space for the puppy - ideally a crate or kennel - which triggers the den instinct in dogs (they keep their sleeping space clean).

Note - Limit crate time to essential unsupervised times of day and ensure your pup has lots of socialization and exercise to develop into a wonderful happy dog.

For more tips and 'How To' information, you can refer your cousin to some of the helpful dog training pages here at Mahalo, here are a few:
http://www.mahalo.com/how-to-potty-train-a-puppy
http://www.mahalo.com/how-to-potty-train-a-puppy-videos
http://www.mahalo.com/how-to-crate-train-a-puppy

Good luck!

As someone who has owned Shih Tzus for a long time, I can tell you taht there is an aspect that is different between the breed, and others. Shih Tzus were raised by monks in the mountains in Tibet, and the surrounding areas. The mountains did not always have a lot of area in which a dog could go to the bathroom. Generations and generations ago the monks taught them to go only in one area. This became instinct.

When teaching a Shih Tzu to go potty, make sure that you choose a specific spot in the yard for it to go to the bathroom. Pick a four foot square section where you want the dog to go. Take the dog out on a leash for the first few weeks and guide it to that area so that it becomes familiar with it. Give it a treat when it goes there. It will become it's section of the yard.

I suggest leaving a small nugget of poop in the area for the first couple of days. That way, the scent is recognized easier by the dog, and it will be more likely to go there again.

Since Shih Tzus are usually nervous when exposed to high winds when going to the bathroom, make sure taht the area that you choose is an area that is blocked from the most common wind direction.

If you live in an area where it snows, make sure that you shovel the snow in the area of your dog's spot. That way the scent can be picked up better in the winter months.

Potty training a Shih Tzu is just like potty training any other dog. It is very similar to potty training children. You must be very consistent the first week of potty training and have your schedule clear. Shortly after feeding your puppy, take them outside to potty. If they go potty, praise them, if not, try again in 15- 20 minutes. Puppies and dogs love routine. Once they get into the habit of going potty outside, your life will get easier. Spend the first couple days going outside often. If your puppy has an accident, firmly say "No" and carry the puppy outside. At night, feed your puppy one last time, and make sure he or she goes potty outside before bedtime. First thing in the morning, take puppy outside to go again.

The real trick is being consistent the first week. If you are, your puppy will be pretty much potty trained by the end of the week.

Is she crate training the puppy at the same time? For my dog we have a set schedule.

I.E

Wake up- Go Out to Potty
Eat
Potty 30 minutes later

He gets fed every 4 hours as he's only 3lbs and a baby still, and then gets taken out to potty every hour to two hours. Also make sure your dog is never allowed loose where you can't see it. My puppy is kept in his crate when we aren't home, make sure it's just big enough for your puppy to turn around and stand up. That way he learns that he can't go potty in the crate, then when I leave and when I come back he gets taken out to go potty.

Some signs of a dog needing to go potty, circling or sniffing the ground or lots of barking at nothing.

As someone who owns a Shih-Tzu I have to tell you from first hand experience that training this breed can be different. They are more "prissy" then some large animals and dog or puppy house training can be difficult for them because of it. I would suggest that since this breed is one that will learn to go in the same spot at all times that she employee this in her strategy. For example this breed is one that is very easily "litter box" trained and there are tons of great things on the market these days that will make this easy to do. If she is not hip on the idea of training them to go in one spot in the home using these great tools then using the same spot in the yard will be helpful. I write blogs on these things often and if she ever needs assistance or wants to get some great tips she can read some of the blogs I write at http://www.unitedonlinebreeders.com in the News section of that site. There are great articles there as well as some other sites if she wants to email the site they have great resources.