Since there is a hound story, I'll add to it:
About 15yrs ago I was running cats in January and there was a hard to get to block that if the river was frozen the cats and hounds would cross and end up in no man's land that was really tough to access if you didn't want to go swimming in January. I had been in this spot once before a couple years earlier and the chase broke up and I was able to call my dogs out, it was always pretty rare that they ended up crossing the river. They came running back out, one had a minor injury from what looked like a stick but I didn't think too much of it as they get beat up a little running through the brush.
Fast forward a few years later and I have a great race going but they went cross country like a bat out of hell and right to the river, I can tell they crossed into no mans land and I hike in to make sure. I look and the ice is really terrible so I can't follow. I give it about an hour and the dogs go out of hearing and are sort of circling one spot but not treeing. This goes on for another 30min or so and I decide I need to go in. I get to a hill and call friend who lives nearby to see if I can borrow his snowmobile to save me about 5mi of walking and time if something weird is going on, he says no problem so I grab the sled and go in coming from another direction that is an old logging road. I'm able to get within about 1/2mi of the dogs and get to hiking in closer to where the dogs are. As I snowshoe in I could tell one of my dogs ran to the snowmobile right away which is fine, I knew he would stay with the machine. I hike into the other two and they are running all over but not really doing anything but I see them covered in blood. I call them over and both dogs have single puncture wounds about as big as my finger and perfectly round, one dog has it in her chest and the other in the rear part of her ribcage. I call them over and we start hiking back to the snowmobile, I can hear my 3rd dog howling where the machine is parked. I get closer and I can see my male dog standing on the snowmobile seat and blood running out of his chest....he also has a perfectly round puncture. I get all three dogs to sit on the snowmobile and I ride out back to my truck. They are bleeding like crazy all over the machine and the front of my hunting coat and pants is also now soaked from having a dog riding on my lap. I get the snowmobile back to my buddy and he sees the dogs and is wondering what the hell happened and his snowmobile has blood everywhere. I give the dogs what antibiotics I have, plug the holes a little, and get them to the vet wondering if they have been shot or what the hell happened! The vet looks the dogs over and is clueless, just says they were obviously punctured with something, but whatever it was didn't break off inside or stay put and it was clean so something likely man made. I tell my buddy about it and that I'm really clueless but something weird went on back there. Drove me nuts, we got significant snow that night so it covered up most of their tracks but I was able to track where they went and found nothing obvious that they would have run into and no human tracks anywhere. There is however deep snow so there is a pretty deep trough where the cat and dogs ran & it would be easy for tracks to blend into that with fresh snow covering them.
Fast forward a year and a half later, my buddy who let me use his snowmobile is hunting bear in that same area with some friends. The bear crosses the river into no man's land and the dogs end up deep into the woods there in exactly the same area, circling all over but not treeing. They figure out a way to hike into the dogs, get in there and 6 bear dogs are running around with perfectly round puncture wounds bleeding everywhere. Take them to the vet, vet says no idea what happened, clean hole like somebody just ran up and speared them.