Biggles was 2 years old when I adopted him from a shelter. I started him on Bifidus, a probiotic, and It took 3 weeks before be stopped pooping in the middle of the day. I continued with the Bifidus in his food for 1 year but he just wouldn't get satisfied. My sister told me about NZYMES.COM and now I use their Antioxidant Treats and Bac-Pak Plus probiotics. It was 2 long years, but well worth it. Now, he jumps in my lap to say "thank you" after each dinner AND he's SATISFIED now.