I watched a friends Chihuahua while they were in jail for a little bit. It was a scared little thing. I have a 35lb Border Collie but he's so smart he knows when to be gentle.

For example my dog loves Tug of War. And when he plays me he tries to yank my arm off. The Chihuahua grabs his tug bone and my dog does to but he just sits there with it while the Chi tries to yank it. He would stand up then sit down to I guess give the illusion of trying. It was amazing.

I'm not a fan of small dogs but I guess I can see the appeal to others.