Diatomaceous Earth is a safe, non-toxic, natural method of preventing internal and external parasites in your dog or cat. The tiny powder destroys parasites without harming you or your pets! The powder has microscopically sharp edges that are harmless for your pet yet lethal to insects and parasites when viewed under a microscope. Since its sharp edges may penetrate and dehydrate parasites, insects, larvae, and eggs, diatomaceous earth has been utilised for decades.