Vet advised change from Science Diet Id solved problem
George was on Science Diet ID diet for some years but in last 6 months he'd had an upset stomach on and off, which then became permanent. Initial treatment with probiotics saw no change so our vet carried out a number of tests and, although he's 18 years old, nothing could be found. She suggested changing from ID to the Royal Canin Gastro Intestinal, which we did over a week, and all is back to normal, and has stayed so. In addition, he's looking better and his activity levels have gone up.