Medical marijuana for dogs and cats is one thing. But medical marijuana for horses!? Yes, its true and its not a new concept in veterinary medicine. Cannabis has been used as a medical remedy for horses across the globe and the sands of time. From the ancient Greeks to modern-day farriers and horse owners, marijuana has been widely employed to successfully address a range of medical problems. There are numerous historical references to cannabis being used for sedation and as an adjunct to anesthesia in equine medicine.