Purina Pro Plan Veterinary Supplements Calming Care contains a strain of beneficial bacteria shown to help dogs maintain calm behavior. The science behind our therapeutic products represents a collaboration between Purina nutritionists, researchers and veterinarians. May take six weeks to see results. Proprietary use of probiotic strain BL999 to help dogs maintain calm behavior. Contains a probiotic with 1X109 CFU of Bifidobacterium longum BL999 per packet to support balanced behavior.