Yeah, that stinks. I've had good luck with my ducks over the years. One hen got attacked and I almost lost her. I had a possum eating their eggs right in the house. I removed him (permanently). The only defense they have is getting closed in at night. As for a goat - one won't do, you'd need at least two for the herd factor or the one will do everything it can to escape. I'm not sure it would deter a coon though. Those things are nasty, nasty, nasty. They will walk right past a goat and steal a bird. The best, and only, deterrent I know of is closing them up at dark and letting them out in the AM.