I'll say that that amount of damage does sound like a pack of large dogs (or even just two or three). However, in my experience, dogs are not usually hungry enough to eat the birds, they are just on a killing spree and while they might eat one or two the rest they just kill.It happened again. Coyote got all 15 of my 4 week old broilers and the hen that was raising them. The coyote ended up moving 30 lb cinder blocks and boulders out of the way, ripping out the wire apron surrounding the meat pen, moved a buried 4x4 log, and chewing off chunks of the plastic (just decorative and sun shade, but still, determined animal), and ended up ripping off a small panel of wire in the corner of the A-frame and getting every single animal in the pen. I'm sick. Despite it's efforts--it kicked those cinder blocks at least 5' away--it didn't end up digging in, but got in where wire was attached between the metal and wood frame. The opening was the size of my hand. I truly believed my animals were completely safe, and their death is completely my fault. I'm just disgusted.
I'm done with meaties for a bit. Honestly, I'm not really sure there was anything further and feasible that I could do to protect their coop. Electric fence doesn't seem feasible in a small space in a suburban yard with kids.
My layers and their coop seem undisturbed. But now I'm not as confident as I was before that the devil coyote can't chew right through the hardware wire.
But I wonder if you have something bigger than a coyote. A game camera would be good. Or someone on watch a few nights, perhaps with some bait out. If you think they are coming over one certain wall, perhaps you could add weld wire fencing to make it taller?
I lost a lot of birds to the bobcat before I caught it. I know that gut wrenching feeling when you walk out to all the feathers and realize what has happened.