ER. Snake bites are tricky. Consensus seems to be a light tourniquet:looser than used to stop a, vein just enough to slow lymphatics.Keep patient calm, a fast heart rate and increased blood pressure speed spread of venom.We never know how much venom was injected.If the snake had a recent meal almost none would be injected. Crotalidae antivenom is very expensive but very effective.
"none" There is no natural treatment for a rattlesnake bite assuming the bite is not "dry" (no venom). Up to 50% of rattlesnake bites involve no venom, however for actual envenomation there is no substitute for anti-venom therapy at the hospital -> the best treatment for a snake bite are car keys! do not cut the wound to suck out venom, apply electric shock, or get bitten again trying to catch the snake!