That’s one of my biggest concerns when I take my JRT out in the woods with me. He’s fearless and will fight with all comers but the big Michigan Coyotes are more than he could handle.
At his size a good sized coon is like fighting a grizzly bear. He’s been wounded fighting coons a couple of times but he’s an optimist.
Being the owner of a JRT my first thought was Jack Russell Terrier Attack’s wolf.
You need to get a Great Dane to protect him. The Dane would become your home’s biggest love muffin. Mine’s right now sleeping on the couch, his pie plate size feet sticking out in front of him.