I have three horses on this product (Omni-WormGuard Plus for Senior Horses) for the past year. Only one time did the older one get a few worms but he eats the grass they poop in so…. The vet called me very impressed and indicated he loves the product-it even causes the eggs of the worms to shrink and dry out. Why give toxic when you can give this and it does such a great job.
Jane A.