How long before manure from a wormed horse is safe for dung beetles and earthworms? I use my horses manure in our vegie garden (after its appropriately aged) and I treasure my earthworms and dung beetles. I've been assuming the fresh manure passed after 48 hours is safe to put on the normal manure pile. I contain the horses after worming for 48 hours and I separately store that "toxic" manure away from the "normal" stuff. I'd love to know how long I have to keep the manure away from earthworms/dung beetles until its safe for them.