unprovoked attack

I moved in with my SO a little over 2.5 years ago, and I brought my then 6mo pitish/mastiff mix puppy with me. She had four other dogs at the time. The dogs were all familiar with each other, and had spent time together no problem before the move. In the first few months my dog pretty...

We have 5 dogs, all rescues, all different breeds from a tiny, Teacup Chihuaua (4 1/2 lbs) to an 18 lb Red Heeler. The three in between are each about 7 or 8 lbs. They've been together for about 8 years and have always gotten along famously. All of a sudden, 3 of the dogs, including the...