Coyotes ganging up
Your story reminded me of another incident that happened to a guy I know. He came home from work, poured himself a glass of wine and let his lab out the back door to do his duty. It was a few winters ago, there had been a heavy coating of snow for several weeks, and it was cold. His property was on the heavily populated main drag of town but it backed onto a large, wooded area. As his dog got towards the back of his yard, he saw what he thought was a german shepherd approach his dog head up. His dog was friendly and started wagging its tail. All of a sudden two more coyotes jumped his dog from each side, going for his hindquarters to hamstring him. The guy streaked out into his yard, yelling as loud as he could. It wasn't until he got within about 15-20 feet that the coyotes finally took off. He had to bring his dog to the vet for emergency surgery--it got dozens of stitches to fix the damage done in a pretty short time. And this isn't in Montana, this is CT!