I have two 13-yr old cats~and have had problems with them not keeping the other foods down, and their stools hard to pass, with stomach aches. This formula seems to have helped them, considerably, in both respects. I will add that I've also added a bit of coconut oil, to the larger one's daily routine; which has facilitated digestion, I believe, also.~EDITED Jan 22, 2015...WHY THE HUGE PRICE JUMP??? Price nearly doubled??