Determine what kind of snake did the biting, if possible. It makes sense to learn about different types in your area. Your primary concern is the horse. Snakebites can be difficult to locate on the body because of the hair, bleeding or swelling, but close examination may reveal fang marks. Venomous snake bites rarely kill horses because a lethal dose of venom depends on body weight.
Most horses are too large for snakes to kill.
Other factors affecting the severity of the bite are the type of venom and location of the bite. Bites on the head and face or areas near a major blood supply are more serious than bites on the legs. The rare fatalities generally occur when the bite is on the muzzle, head or neck. These often result in swelling which can close off the airways. If your horse gets bit, keep it calm.