I've been raising chickens here since 2010 and we've only had 2 major predator attacks and they were both dogs. Yes, we've had our share of persistent foxes or raccoons over the years, but dogs take the prize for the sheer amount of casualties they cause in one go.
The worst part about dogs, is that they run chickens down for fun! I can at least understand a fox or coyote that has to eat, but dogs just chase chickens for sport and somehow that's twice as devastating!
The first time it happened was about 7 years ago. It was 3 dogs that someone had brought with them to visit one of our 'neighbors' and they just let them run every morning. Their excuse was that the dogs never get to run off leash in the city and they didn't think they could get into any trouble, it's just woods. *sigh*
Except farmers live in between those stretches of woods and homesteaders actually live on acreage in the woods! They never even considered that some of us have farm animals and the dogs had never seen them before so they would be curious. Spoiler alert...if your dog chases cats and bunnies in the city, they're chasing livestock in the country when they get the chance!