There are many different venomous snakes. Know the kinds of snakes you have in your area and what the dangerous ones look like. It’s not always easy to tell what kind of snake bit your dog, but if you do know, it can help your veterinarian determine the best treatment. In North America, there are four principal kinds of venomous snakes: rattlesnakes, cottonmouths (aka water moccasins), copperheads, and coral snakes. Snakes You May Encounter in North America Rattlesnakes Rattlesnakes live in a variety of habitats. They can be found in deserts, forests, and wetlands, from sea level to mountain elevations.