Your dog or cat's immune system can become weakened for various reasons. It is important to support your pet's weak resistance. L-Lysine Comp from Phytonics can contribute to this through its essential ingredients. L-Lysine is important for tissue growth due to its collagen-forming properties and ability to absorb calcium. Vitamin B6 and Vit C are co-factors for the absorption and intracellular action of L-Lysine. The product is suitable for cats and dogs.