Dangers of Sodium Bentonite Cat Litter

Is Sodium Bentonite Cat Litter Killing Your Cat?

Cat litter manufacturers cannot possibly be unaware of the dangers that sodium bentonite cat litter poses to cats. If there’s one thing you can be sure of, it is that cats will lick themselves after using the bentonite clay because this clumping variety of litter will stick to their paws. Every time your pets visit the litter box, they ingest the cat litter through inhalation and licking.

The litter accumulates in their stomach and swells, forming a hard lump that renders the stomach to the same state as blocked plumbing. The body will try to cleanse itself through repeated bouts of diarrhea during which time the stomach can hardly absorb any nutrient.

Unfortunately, only the diarrhea is diagnosed by most doctors, and medicines are prescribed upon such diagnosis. The patient eventually succumbs to a very painful death.

The only treatment is to remove the cat from the litter, and then to put the patient on holistic treatment using soothing laxatives to get rid of the poison. During this time, it is best to feed homemade chicken or fish broth or stock. If the treatment begins early, recovery is a distinct possibility.

Types of Cat Litter

Currently, apart from the organic varieties, there are three main categories of cat litter: clump, silica crystal and the plastic crystal varieties. The last one is used by Cat Genie automatic litter box and it is reusable (until you have to replace it). The first two types are used by Litter Maid, a Self Cleaning Litter Box.

Apart from these two leading brands, clump and crystal cat litter are sold by various companies, either as a standalone product or as recommended litter for the specific brand of cat litter box.

Sodium Bentonite Cat Litter

The clump variety of cat litter comes as grainy particles that absorb the liquid from the excreta and also control the odor by forming clumps which can then be scooped out and replaced.

The most powerful clumping substance is Sodium Bentonite, a certain type of clay that swells up to 15 times its volume in the presence of water and is, therefore, extremely effective as cat litter.

Today, more than 50% of the cat litter sold in the U.S. is of the clumping variety, and most of it is made from bentonite clay which is usually procured through surface mining – a process detrimental to the environment. We are warned against flushing sodium bentonite cat litter as the cement like clumping property can block plumbing.

Is there any evidence sodium bentonite litter is bad for cats?

The now defunct Cat Fancy magazine carried an article by A. D. Shojaim, How Cat Litter is Made in its October 1994 issue. The following is an extract:

‘Sodium bentonite, a naturally swelling clay, is often added as an extremely effective clumping agent. When liquid is added, bentonite swells to approximately 15 times its original volume. But because sodium bentonite acts as an expandable cement would, litters containing sodium bentonite should never be flushed; when they expand they can block plumbing.’

Curiously enough, the article made no connection between possible internal blockage that a living being may develop if sodium bentonite litter is ingested. Perhaps, the author did not take into account the possibility that cats could accidentally (while grooming themselves after having visited the litter box) or willfully (as is frequently the case with kittens) ingest this litter.

Voices of dissent against sodium bentonite clumping litter

Marina McInnis, in the January/February 1995 issue of Tiger Tribe: Holistic Health & More For Cats writes about a mysterious disease that kept plaguing (and often killing) her kittens. She finally connects the symptoms to the clumping litter and replaces it with an organic litter. The patients are finally cured through holistic medication.

An updated version of her story may be found here.  In her write-up she refers to Shojaim’s article in Cat Fancy magazine. She also has archived on her site hundreds of letters from cat owners thanking her for saving their cats’ lives through this one article.

But of course, those letters are not scientific evidence and neither is her ‘story’.

It may be pertinent to note in this context that clinical evidence of (suspected) bentonite toxicosis in a cat is published for the first time in the public domain by Marina as well.

Stanford University’s eco-advice column answers a query in December 2007 on choosing cat litter. It talks of hazards of sodium bentonite litter and suggests alternatives.

There’s an article on About.Com that speaks at length of problems related to bentonite litter and also refers to Marina’s article as where the dissent originally started. I could not find its date.

In late 2011 I started this blog on my earlier domain

The number one reason clumping clay litter is considered safe

Dr. Elsy’s sums this up beautifully:

Concerns that bentonite clays will “set-up” in a cat’s stomach are un-founded. Over half of the litters sold today include bentonite clay and have proven safe for cats since their introduction over fifteen years ago. In fact, the convenience of clumping clays have contributed greatly to the growth of cats as pets. In Dr. Elsey’s 25 plus years as a feline only veterinarian, he has never had a case where clumping litters have caused a problem with a cat.

In other words, there is NO EVIDENCE that sodium bentonite clumping clay litter may be harmful to cats. Anecdotal evidence, of course, doesn’t count.

Interestingly, Dr. Elsy’s says the following to the question ‘Are your litters flushable?’

No! DO NOT FLUSH our litters. These litters are designed to form hard clumps. A “flushable” clumping litter is a contradiction. If it dissolves or breaks apart in a toilet, it will break apart in a litter box. A true clumping litter is more convenient for you and better for your cat.

Cat’s Pride (a flushable litter that claims not to clump as hard as sodium bentonite litter) echoes Dr. Elsy’s in support of bentonite clay:

Any suggestion that sodium bentonite will cause harm or fluid retention in cats is simply not accurate and has never been documented in the veterinary scientific community.  In fact, numerous consultations, interviews, and tests by many vets have found no evidence relating normal use of a clumping/sodium bentonite litter with the sickness or death of any kitten or cat. For additional information visit

Again, there’s NO DOCUMENTED EVIDENCE that sodium bentonite is harmful. By the way, don’t bother clicking the link at the end of the quote, it leads to a page not found error.

And, of course, without documented evidence, the following cannot possibly be connected:

  1. Bentonite clay should not be flushed because it is like cement and can block plumbing
  2. What may happen if a cat’s system tries to ‘flush’ or excrete bentonite litter after eating it
  3. What may happen if a cat were to eat anything that is cement like

Research on effects of sodium bentonite litter on cats

There’s something interesting going on here.

Absence of documented evidence may imply that research conducted in this area yielded no evidence.

However, there isn’t any research that investigates what happens when cats eat clumping litter.

Anecdotal evidence that sodium bentonite clumping litter is harmful to cats is not acceptable because we need documented evidence.

But anecdotal evidence that no cat has ever been harmed by bentonite litter is more than enough to ‘prove’ that such litter is completely safe.

Just for clarification:

In Dr. Elsey’s 25 plus years as a feline only veterinarian, he has never had a case where clumping litters have caused a problem with a cat.

is anecdotal evidence.


…numerous consultations, interviews, and tests by many vets have found no evidence relating normal use of a clumping/sodium bentonite litter with the sickness or death of any kitten or cat.

is evasion.

No one claimed that normal use of any litter ever harmed a cat. Cats ingesting bentonite litter while grooming themselves or kittens playfully eating clumping litter on purpose are not normal uses of cat litter. Yet they happen all the time.

And we are back to where we started in this vicious cycle: there’s only anecdotal evidence of deaths caused by sodium bentonite clumping clay litter.

How can you tell if a litter has sodium bentonite in it?

Some manufacturers clearly state that their products contain sodium bentonite, others don’t. If you find a ‘clumping’ litter which also has the word ‘clay’ somewhere in its list of ingredients, it probably has sodium bentonite in it. When bentonite is not present and the litter is made of clay, you are unlikely to find the clumping property emphasized.

You might also want to read about Organic Cat Litter

Update: August 2016 –

Is Sodium Bentonite Cat Litter Good for anything at all?

Apparently. Bentonite clay and other, similar ingredients found in inorganic cat litter have effectively stabilized and absorbed liquid nuclear waste for years. It is possible that sodium bentonite cat litter has absorbed more ammonia and urea from nuclear waste than it has from kitty pee (!). This came to light after an unfortunate incident at the New Mexico Waste Isolation Pilot Plant (WIPP). Workers had arbitrarily replaced the usual inorganic cat litter with Swheat Scoop which is made from wheat. According to James Conca,

Cat litter has been used for decades in radiochemistry labs and nuclear facilities to stabilize certain radwastes, like liquid scintillation solutions, evaporator bottoms, and other materials that have nitrate salts in solution.

Nitrate salt solutions can ignite when they dry out – which is why it’s tricky working with nitrate solutions in the lab and why you need to make sure they don’t dry out, something many a chemistry student has found out the hard way. So you need to stabilize nitrate solutions before they dry out, or prevent them from completely drying out.

The organic litter was not equipped to stabilize the nitrate salts and dried them to the point of ignition. Well, this was in 2014 and on Valentine’s Day, no less. Thankfully, there were no fatalities and the radiation released was not strong enough to cause environmental concern. WIPP, in spite of performing flawlessly for 15 years, was shut down after the incident and last I heard, it was supposed to reopen this year (2016).

Clumping is not the Problem

Cleaning the litter box and replacing used litter is made extremely convenient if the litter clumps. The problem, therefore, is not the property of clumping but the agent used. This, of course, is easily overcome by switching over to an organic clumping material. There are a number of organic clump litter available.  Natural Wheat Cat Litter from Swheat Scoop is what we can probably vouch for (as long as you promise to NOT use it to absorb anything but feline waste!). Probably, because even though we use wheat scoop, it is not Swheat. We purchase the chaff of wheat from wheat grinding mills in our locality and so far, the stuff has been more than excellent as litter.

The litter ‘box’ in our shelter is basically shallow trenches dug in the ground and filled with sawdust and wheat chaff with a bit of citronella oil thrown in for odour control.

Recycled newspaper, wood shavings, sawdust, wheat chaff – anything organic that will not behave like cement is good litter for your fur baby. Please read our post on ORGANIC CAT LITTER for a list of safe cat litter brands.

Even silica crystals are not safe and, apparently, they are responsible for affecting the lung tissues of the cat with lesions eventually causing cancer of the lungs or the throat. Please refer to our post on the Problems of Silica Gel Cat Litter if you wish to know more.

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2 thoughts on “Dangers of Sodium Bentonite Cat Litter

  1. Hi, My cat started have problems, eg: loose stool; vomiting often with hairballs and then w/o hairballs, but a greyish/yellow frothy substance; wouldn’t eat and had no energy. Took him to the Vet …$$$$. I then read about sodium bentonite on the web. I got rid of both litter boxes of the clumping litter and re-filled with a non-clumping wheat chaff material. My Wife and I force fed our cat a couple of times that evening. I also did a thorough vacuuming and mopping of the floors (I’m retired, but my Wife isn’t so our family responsibilities have changed a good deal). The result was, to say the least, unbelieveable. The next day the cat went to his feed bowl and sat to be fed, as usual. He ate 2 tablespoons of the Vet canned food and hasn’t vomited yet (3 hrs.). GET RID OF YOUR CLUMPING CAT LITTER !!!!!!!!!!! I can’t say this strongly enough. Take care, Rich

    • Thanks for sharing your experience with us, Rich. And I’m sorry my reply comes so late – haven’t updated or even looked at this blog in ages :p

      Hope your fur baby is bouncing around happily, now 🙂

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