Search Search Search You must have JavaScript enabled to use this form. Topic Equine Welfare (-) Keeping Horses Safe (-) Toxicology & Poison Control Active FiltersKeeping Horses Safe Group 9 Toxicology & Poison Control Group 9 Clear All Reduce the Risk of Feeding Horses Contaminated Hay While horses may normally avoid ingesting noxious weeds or moldy hay, they can be more likely to ingest them when mixed into their feed.