Review on Hill's Science Diet Dry Cat Food for Senior Cats: Chicken Recipe, Adult 7+ - Essential Nutrition for Aging Feline Friends by Lauren Lewis

I have been using this product at home with both old and young cats for a number of years. After researching information online about cat food, I tried Nutro Senior in two different flavors for several months (in addition to continuing to offer this one). They seemed to like this change, but after a few months one of my young men started urinating all over the place constantly, with blood. The vet diagnosed struvite/triphosphate crystals in the urine and sent us home with (expensive) prescription diets (several brands). what they gave us and the symptoms disappeared. I used the urination formula and after Nutro was exhausted I also suggested the original scientific diet (active longevity) that I had used before and we haven't had any issues since. I saw him eat both diets. I have come to the conclusion that this product (Active Longevity) does indeed maintain the correct pH of the urine to prevent the formation of the most common crystals found in cats.