Our 100% whole, organic Turkey Tail mushrooms for dogs are third party tested to be high in beta-glucans. Enhances the immune response Supports a balanced immune system Guaranteed minimum 50% beta-glucans Beta-Glucans For Immune Health The fruiting body of the Turkey Tail mushroom contains very special beta-glucans called Polysaccharide-K (PSK) and Polysaccharide Peptide (PSP). These potent immune-enhancing substances make Turkey Tail a game-changer for any dog with immune stresses. Tested for potency: Every batch of our mushrooms is extensively tested to contain a minimum 50% beta-glucans for a super-premium mushroom supplement your dog will love. No hidden starches: Made from pure turkey tail mushroom extract with no fillers or unnecessary carbs. Grown naturally: While most "mushroom" products are myceliated grain grown in plastic bags, our certified organic mushrooms are grown in greenhouses on wood and natural substrates and free of synthetic fertilizers and pesticides - just like nature intended.