Toxicity to pets

Rattlesnakes are found throughout certain regions of the world, and their bites can be deadly to animals. In the United States, common examples of rattlesnakes include the Eastern Diamondback, Mojave, and Timber Rattlesnake. Due to their curious nature, dogs and cats will approach a rattlesnake leading to snakebite on the pet’s face or front legs.
The best way to avoid a rattlesnake bite in a dog is to keep your dog on a short leash when hiking in “rattlesnake” country.

Clinical signs of envenomation include pain, difficulty breathing, blood clotting abnormalities (e.g., bruising, bleeding), skin and muscle injury (e.g., swelling, tissue death at bite location), cardiovascular shock, organ failure, and death.