Okay get a .22 rifle, get 5 condoms, climb up to your roof, put 1 condom over the tip of the barrel, aim right behind the ear, squeeze the trigger and repeat until dog stops barking. You may need more fire power but at 20 feet you should be okay.
If that fails get a .40 cal hand gun, knock on your neighbors door, when they open the door put 2 rounds in the chest and one in the head, walk through the house, open the back door, and give the dog some water
Let me know how it goes..
Edit: Whatever you do don't call aspca, nobody likes a snitch