ORIGINAL: jerrrrstanley
The Code of Virgnina can be found on the VA State Police website. The Code section you are looking for is 3.2-6570 Cruelty to animals. It is a class 1 misdemenor to kill or injure an animal. If its a second offense in 5 years,or a companion animal, its a class 6 felony. Now i don't know what the court thinks a companion animal is but i don't think its a hunting dog. Also, its not illegal to defend your animals or livestock by deadly force if a dog is attacking your animals.
I had heard, in wake of the Vick case, that killing a dog in VA is now a felony. I'm unsure of on what level. I'm sure hokie man knows.
As to defending livestock, in western states, its common knowledge and practice that a dog that chases livestock or horses is dead and doesn't know it yet. As to VA, I'm not 100% on what the law is... but when it comes to defending yourself I'm sure the law will be on your side as long as you are honestly defending yourself or a third party.