The Organic Turkey Tail concentrate full-spectrum mushroom extract (grown by organic traditional cultivation) may support your dog's immune system. This hot-water-extracted mushroom may balance your dog's digestive system, help maintain a healthy immune system and they are a great source of antioxidants. With organic traditional cultivation, you can be sure that the mushrooms are full of phytonutrients and beta-glucans. Research shows the PSP extract from Turkey Tail mushrooms may provide a longer survival time for dogs with hemangiosarcoma. The PSP extract was found in a study at the University of Pennsylvania Veterinary School to provide longer survival times for dogs with cancer in their spleen.