My trainer days that my Shih-Tzu messes in her crate because she uses a potty box inside. What do you think?

My continued research carried me to your great web site.

Female senior citizen and first time dog owner purchased a female Imperial Shih-Tzu (the shadow), 6 weeks old - now 5 months old. She is very precious, smart, funny, lots of personality, etc. For many reasons I wanted to train her to 'go' inside in a potty box.

I am using an in-home trainer. He used the leash training first and is now going into off leash training and she is doing great in those regards. My big problem is the potty situation and he thinks it is because of the potty box. For almost 4 months it's the same pattern: Angel's last meal is around 3:00-4:00 pm, she potty's at 10:00-10:30 pm, sleeps in a small locked crate in the laundry room [poops in the crate], has to be shampooed and the crate washed every morning. She is so tiny, how could she even have anything left in her stomach. No one is giving her 'people food' and nothing to eat after her last meal. She eats Muenster Puppy dry dog food.

The trainer says she is confused because of the potty box and just thinks she is supposed to go in the house (says I will have to give it up). He instructed me to leave her in the dirty crate for several hours instead of rewarding her with a nice warm shampoo. This was hard for me to do so he took her home with him for 10 days to see if he could get her straightened out and currently has her 'going' outside, but she still goes in the crate even at his house. She went 5 nights with no mess and then just when he was going to bring her home she did it on night #6 (he has had her 20 days).

Your answer to a question on your web site. shed a new light on the subject: maybe her breeder left the Mother and puppies in a dirty environment for that first 6 weeks and she thinks that is the way to live.

Can the problem be corrected? Isn't it taking a long time? Please advise on these issues and also your opinion of using the potty box.

Thank so much for your time,
Jerri