The Rx Vitamins Liquid Immuno Dog and Cat Immune Support is a delicious and easy-to-swallow formula that is designed to help support and improve the function of your feline or canine immune system. This formula is made with a unique blend of l-lysine, reishi mushroom extract, and chicken flavor that is perfect for supporting your pets’ immune systems. The liquid format makes it easy to give this to your pet, and the fact that it is designed to be consumed orally means that it is safe for use even in large dogs.