Is he new to wearing bows? Maybe he's just not used to them yet. The best way to get him used to them is to distract him after you put his hair in a topknot until he forgets about it. That would be a good time for a walk or a Greenie - anything to get his mind off his hairdo!
What kind of bands do you use? Could they be itching him? I have always been stickler for good bands since Lady wears a topknot 24/7 and has done so for over 5 years. I have never had a problem with breakage, baldness, etc. I get all my bands from the Finishing Touch. I get the 1/4 inch medium weight bands. They are the same bands I use on the backs of my bows.
My vet told me something yesterday which convinced me that the type of bands/bows you use is important. She always comments on Lady's bows, but really to Lady, telling her how cute her bow is, etc, so she wasn't aware that I made them. Yesterday when I took Lady to have her eye rechecked, she really checked out Lady's Jack-o-Lantern bow and finally asked me where I was getting such "high quality" bows. It turns out she saw a Shiz Tsu last week who had lost all the hair in the back of her head, it had completely "died" and would never grow back, all from wearing top knots with poor quality bows.
Now, as flattered as I was for her seal of approval, I know the type of band I use is really what protects the hair, no matter how cute or clever my bows are! I also do Lady's topknots according to JMM's tutorial, with the papers, and loosen them with a rat tail comb like she suggests, which is also important.
So any of you who are using bands from your child's braces or cheap bands from Walmart might want to consider ordering the real groomers bands. And be sure and review JMM's wonderful tutorial: