My older indoor cat has become allergic to grains in regular dry cat food. He threw up everything he ate of it. His vet had me buy another grain free food, expensive but worth it if he would eat it. HE WOULD NOT. A relative that worked at a pet store told me about Blue and how fast it sold. I tried a small bag and my kitty loved it. Its expensive but remember it isn't full of fillers and it lasts so much longer because less carbs means less hunger. As an added bonus, less litter box using, less odor..
We were using another product in which we could see tiny critters moving in the cat's bowl. We learned that these were common in dry food and that they were grain mites. So we have been buying this grain-free dry food since and have not seen the little buggers. Besides our cat eats it, so she approves!