It is weird after growing up on a farm and walking outside to see my dog piled with cats. Mine just hate all dogs. Strange that yours have chosen a victim. Such bullies! You should make a feline Mean Girls movie!
I want to get a dog or puppy really badly, but I too have four female cats. The white one, Twinkie poofs up to racoon size on sight of a dog and rides intruder dogs out of my yard. It's funny when they're interlopers but I don't want to drive them away or get a pooch only to have the crap beat...