Mississippi Code Title 41. Public Health § 41-53-11

(1) It shall be lawful and it shall be their duty for any sheriff, conservation officer or peace officer of a county or municipality to kill any dog above the age of three (3) months found running at large on whose neck there is no such collar and tag. No action shall be maintained by the owner for such killing. However, it shall be the duty of said officer who finds a dog or dogs running at large to first keep said dog or dogs for a period of five (5) days and notify the sheriff of said county that he has said dog or dogs, giving the sheriff a description of same. If anyone proves himself to be the owner of same, he shall pay said officer the sum of fifty cents (50¢) before the dog is delivered to the owner.

(2) It shall be the duty of any sheriff, conservation officer or peace officer of a county or municipality to kill or otherwise destroy any and all dogs above the age of three (3) months which are running at large and have not been inoculated (vaccinated) as required in this chapter.