The majority of snakebites occur on the legs or head, usually when cats are playing in snake-infested areas and elicit snakebites by aggressive or curious actions. Even though a venomous snake may have bitten your pet, not all bites contain venom. Less than half of all snakebites result in signs associated with envenomation, pain, bleeding, swelling and collapse. Rattlesnakes, water moccasins and copperheads are most commonly associated with snakebites. Antivenin is available and recommended for rattlesnake bites. For copperhead bites, antivenin is generally not recommended and rarely needed.