You are wrong about Virginia, VA's law is pretty much the same as Maryland's.
§ 3.2-6552. Dogs killing, injuring or chasing livestock or poultry
It shall be the duty of any animal control officer or other officer who may find a dog in the act of killing or injuring livestock or poultry to kill such dog forthwith whether such dog bears a tag or not. Any person finding a dog committing any of the depredations mentioned in this section shall have the right to kill such dog on sight as shall any owner of livestock or his agent finding a dog chasing livestock on land utilized by the livestock when the circumstances show that such chasing is harmful to the livestock. Any court shall have the power to order the animal control officer or other officer to kill any dog known to be a confirmed livestock or poultry killer, and any dog killing poultry for the third time shall be considered a confirmed poultry killer. The court, through its contempt powers, may compel the owner, custodian, or harborer of the dog to produce the dog.
Any animal control officer who has reason to believe that any dog is killing livestock or poultry shall be empowered to seize such dog solely for the purpose of examining such dog in order to determine whether it committed any of the depredations mentioned herein. Any animal control officer or other person who has reason to believe that any dog is killing livestock, or committing any of the depredations mentioned in this section, shall apply to a magistrate serving the locality wherein the dog may be, who shall issue a warrant requiring the owner or custodian, if known, to appear before a general district court at a time and place named therein, at which time evidence shall be heard. If it shall appear that the dog is a livestock killer, or has committed any of the depredations mentioned in this section, the district court shall order that the dog be: (i) killed immediately by the animal control officer or other officer designated by the court; or (ii) removed to another state that does not border on the Commonwealth and prohibited from returning to the Commonwealth. Any dog ordered removed from the Commonwealth that is later found in the Commonwealth shall be ordered by a court to be killed immediately.
The recent case in Va where the man was convicted of animal cruelty for shooting the dog killing chickens. The guy used birdshot, and it was proven he was familiar with guns and ammo and knew that birdshot would not kill a dog but would only cause pain and suffering, SO perfectly legal to shoot to kill, not legal to shoot just to injure and cause pain.