Is Ragweed poisonous to horses

No. Common ragweed (Ambrosia Artemisiifolia) is not poisonous to horses. Horses and cows will occasionally eat ragweed, though usually when other roughage is scarce. The 50+ horses on our farm eat it, and I've never had any problem with it, and the donkeys at my house consider it a delicacy. Wild cherry, however, is highly toxic to horses (when the leaves are wilted Though most savvy horses avoid it, if you see your horse eat some wilted leaves off a fallen branch, call your vet. If you are worried about the plants growing in your pasture, check a list of poisonous plants for your area to access the danger. Just use common sense, most horses will avoid things that they shouldn't eat, unless they're starving.