Purina Pro Plan Veterinary Diets FortiFlora Chewable Tablet Supplements contain a safe and effective strain of beneficial bacteria proven to promote normal intestinal microflora. FortiFlora is the #1 probiotic brand recommended* by veterinarians. The science behind our therapeutic products represents a collaboration between Purina nutritionists, researchers and veterinarians. *Kynetec, Probiotic Recommendation Study, March 2019