This litter (Dr. Elsey's Cat Ultra Premium Clumping Cat Litter) contains 'bentonite' clay, which is according to a published article in the journal of 'Veterinary and human toxicology'; cats that eat bentonite-containing cat litter are predisposed (more susceptible) to anemia with an associated elevation in their reticulocyte counts. If you want to read it yourself, here is the article title: "Suspected Bentonite Toxicosis in a Cat from Ingestion of Clay Cat Litter". You can look it up on Google Scholar and see what research (and not a company who wants your money) tells you. My cat's blood test returned with HIGH reticulocyte counts. I never thought about his litter at all, but then I started investigating every single thing he is recently used, and the litter was one of them because I changed it recently after I moved to a different area where the litter I usually use was not available. PLEASE, do not risk the health of your cat. I regret the moment I bought this a lot. My cat is sleeping in the hospital right now. I have been using it for around 4-5 months now, and the effect showed just recently because of the cumulative and gradual effect of ingesting the litter by grooming. If you are using it, you do not have to throw it right away (probably much more safer to do so though), but at least don't buy it again if you care about your cat's health. And ESPECIALLY if your cat has a history of Anemia. I will make sure to warn people from this litter in every website I have bought this from, or wherever I can write a review about it. I couldn't even imagine that my cat will be hospitalized one day because of his litter until I found that article. Graduate school taught me to look for reliable sources whenever I am confused, and I am glad I did. This litter is indeed and by all means natural, but please note that: Natural DOES NOT equal safe. Toxics found in plants, poisons in many mushrooms for example or even snakes are natural, parasites are natural, dangerous bacteria are also natural, etc. Don’t let the naturalistic fallacy fools you!