I feed Cat Chow Indoor Formula as well and have had *less* hairballs, vomitting, etc than I did with the more expensive brands, including Iams, Science Diet & Eukanaba, as well as Flint River Ranch food. There is less food coloring in the Indoor Formula.

Also, their poop is more solid and less smelly on the indoor formula. You can tell how good a food is by how frequently they poop. If the nutrition is good, they will have less waste. If the food is horrible, they'll go to the bathroom more frequently because they're not getting the nutrition and it's being wasted.