Instinct always takes over, not common sense (with me, anyway!) I know how to break it up (either pulling back legs or using the "chuckit" against their throats) but I did the same when a dog attacked Chloe at the dog park the other day. I instinctively reached in to grab a dog, and got bitten on my hand for my efforts. Thankfully no skin was broken but I had the most painful huge bruise for over a week and it's still sore. Not smart being a musician and having trouble playing at the moment.

Someone grabbed my Chuckit and did the throat thing to break up the fight. Same bloody dog attacked Chloe a few weeks previously, and a few other dogs at the park. Owner did NOTHING, but eventually left.