I have a Doxie as well. Doxies are very :blob4: hyper doggies. So, I found a solution that helped her.
The first night I had April home. All she wanted to do was cry, she did not want to sleep. I kept her fenced up in my kitchen and I had a clock ticking. However, she still would not relax. Finally, I got up in the middle of the night and tried to console her. (not the smartest thing to do, because then she expects it all the time). But, she finally went to sleep, I put her in her bed, with a stuffed animal, that was bigger then her, and she finally went to sleep.
The next night, I wore her out, ran her all over, introduced her to many new things, and she was having a blast. When it was time for bed, I again had the clock and stuffed animal and she went right to sleep.
The third night, and all the nights after, she found that when she goes to sleep, even though she is by herself at night, I come to see her in the morning. She got used to that. So, now she goes to sleep no problem.