What are some green ways to deal with parasites?

Try Natural Defense products for fleas and ticks. Use diatomaceous earth, (the kind that can be eaten) in the garden to get rid of pests. Practice good hygiene. Don't allow your pet to eat anything from the ground. Clean poop up as quickly as possible.Don't let your pets drink from puddles, any standing water, even lakes and rivers. There are herbal teas available that can cleanse the digestive tract,but make sure they are safe for pets.