Happy Tummy For Horses & Ponies - A feed additive that takes toxins out the horse's system naturally - Charcoal based - Reduces the load on the immune system Happy Tummy charcoal is a potentised feed additive which take the toxins out of the horse's system (naturally). This reduces the load on the horse's immune system which can then proceed to clear up most ailments. A strong immune system is the basis of a good health and by unburdening this, Happy Tummy helps address a wide range of health problems. It's inexpensive, very effective, and can save you a fortune.