RE: What do leg traps do to the legs of the animal?
Your local trapping association or other public representation group will ask you to refer to the trap as a FOOT HOLD, primarily because clueless people think a "leghold"will snap legs off.
I use a #3 Bridger with #4 springs all the way around it... very few traps on the market are that strong. I caught one of my 7 week old beagle pups while testing traps at the house. No broken bone, no pain after a day of limping.