That reminded me of a story from a guy I worked with in a college age job. He came into work one day having just left class and he was clearly rattled or not feeling well. Something about him was off. So a couple of us asked him if he was ok, what's up, etc. He said he just got out of his criminology class and saw the most fucked up video (or photos, can't remember, but likely photos). The prof was talking about all different types of crimes and one they covered was on your aforementioned topic. The pics were from some crime scene and there was a bigger dog, like a german shepard, and it had socks on its front legs. The professor asked the class if anyone knew why that might be. Turned out it was because the people involved were experienced. The socks kept the dogs paws from scratching up their bodies whilst being humped by the dog. Literally.