When I saw your post it made me grin thinking about Jay Leno and how much he HATES seeing pets in clothes! He often mentions it on his TV Late Show. It's a huge "pet peeve" of his - haha!
Anyway, we've never dressed up any of our animals - no one in our entire family has. We have been discussing getting our Tonkinese cat a coat though because he is cold all winter long inside the house. He has very little fur (nice for keeping shedding down to a bare minimum!) and is always on top of the bird's heater during the winter time. I'm just not sure he'd take to wearing clothes though.
I just think if an animal shows distress when you're doing something unnecessary to it - don't do it!