Another suggestion would be to run a hot wire around your property or enclosure- one strand should be enough to deter a dog, and it's way cheaper than a full fence. The main problem is that once the dog has learned that you have delicious treats roaming around your yard, it will keep coming back...
While I fully advocate shooting the dog, it's easy to say that when I don't have to live next door to them after I kill their pet. Perhaps a more humane solution would be to invest in a humane type trap, bait it with something the dog would like, then bring the "found" dog to a humane society...