It is my professional opinion that Equine Defense System is an extremely well formulated herbal supplement that works to boost the horse's immune response and to improve general health and well being. I have seen horses with known susceptibility to specific health conditions, primarily skin disease, have improved resistance and less severe reactions while being supplemented with Equine Defense System even when exposed to previously inciting circumstances. I believe that the herbals combination in Equine Defense System works to stimulate the immune system, and is highly effective when used in conditions that may be considered stressful to the horse. Lisa Kostandoff, DVM Horseowner, Toronto, Canada Equine Acupuncturist