Beta-glucan is a polysaccharide isolated from the walls of Sacharromyces cerevisiae yeast, which has a unique ability to stimulate the immune system, while being completely safe for the body. Receptors located in the digestive tract recognize beta-glucan molecules, thanks to which all natural immune defense mechanisms are stimulated, and the animal is better prepared to fight germs that could enter the body. HMB-Ca, or beta-hydroxy-beta-methylbutyrate calcium, is a metabolite of the amino acid leucine that has been shown to support muscle health and immune function in dogs and cats. It also has anti-inflammatory properties that can help to reduce oxidative stress and inflammation, which can negatively impact the immune system. It stimulates phagocytic cells, increases the number of antibody-producing cells and increases metabolic activity of immune cells.