Royal Canin Veterinary Diet Calm formula is designed for dogs under 33 pounds. It includes two amino acids that help pets maintain emotional balance. Alpha-casozepine is an amino acid chain derived from milk shown to have calming effects. L-tryptophan is a more commonly known amino acid that also has calming effects. In addition, the formulas include Nicotinamide, also known as Vitamin B3. Nicotinamide creates a calming effect within the central nervous system. It's also formulated to meet the nutritional needs of dogs facing digestive, skin and urinary sensitivities.Royal Canin