Yeah In the ditch but cover it over. Bury, burn, or bag and toss in trash.
Even a dead animal with mange can/will still pass it on.
Its not likely you'll get scabies (mange) just by touching it. I handled a bunch of fox and coyotes with mange without gloves and never got it. I would wear gloves if you have them though. I try to keep a few pair of gloves in my truck. One for setting, one for lure, and one for handling my catch.