Whether or not clumping kitty litter is a health hazard for cats is a
matter of some debate. Since there haven't been any clinical studies,
it really comes down to who you ask and which brand you're asking
about. Most of the current controversy swirls around brands which use
Sodium Bentonite, a highly absorbent clay. Brands that do not contain
Sodium Bentonite seem to be considered safer.
Personally, I won't use either. When one of my feline owners began
suffering respiratory infections shortly after he adopted me, his vet
suggested ditching the clumping litter due to dust concerns. We
switched from the clumping variety to the crystal kind, and
Bailey-kitty's woes vanished. Not scientific, to be sure, but enough
to convince me that clumping kitty litter may not agree with all cats.
Here's what opponents to clumping litter have to say:
" Clumping clay litter, which forms a hard ball when it gets wet, is
one of the most harmful types on the market. Several brands use this
clay to make thier litter easier to scoop. What makes it clump? It's a
natural clay ingredient called sodium bentonite. In this case,
"natural" is not always safe. Here's the problem: When this clay gets
wet it expands and forms a hard mass. So when your cat or kitten digs
in the litter box it's stirring up clay dust and breathing it in. Once
it gets into their lungs, it expands from the moisture, and in time
builds up, causing all sorts of lung problems like the ones mentioned
Some clumping litters actually post a warning right on the bag; "Do
Not Let Cat Ingest Litter". It is ridiculous to think that you can
stop your cat from breathing while visiting the litter box .You cannot
stop your cat from grooming itself with its tongue or stop your new
kitten from swatting and nibbling on the litter. Anything their tongue
contacts gets ingested. Once the clay litter is inside the cat or
kitten and expands, it not only could cause dehydration by absorbing
all the body's moisture, it could also form a hard mass in the
intestines over a period of time, which could be fatal."
Kitty Litter with a Serious Warning (via the Internet Archive)
"[...] respiration problems are not the only thing to consider when
purchasing litter for your cat. All cats clean their fur and paws,
which can be coated with clay litter from using the litter box.
Clumping litters in particular can be harmful to your pet because,
once ingested, the litter expands and absorbs moisture in the
intestines, causing blockages and dehydration, and preventing the
absorption of nutrients. For this reason, the ASPCA recommends not
using clumping litter for kittens."
From Rainforests to Kitty Litter
"An article entitled "How Cat Litter is Made" appeared in Cat Fancy
magazine (October 1994). Shockingly, the article contains no cautions
against the use of clumping litters, even though the description of
one of the main ingredients in such products should be enough to alarm
any thinking person.
"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."
A few moments' thought is all that is needed to realize that something
able to block household plumbing must be wreaking havoc on the
plumbing of our feline companions."
Clumping Clay Kitty Litters: A Deadly Convenience?
"There has been a rise in depressed immune systems, respiratory
distress, irritable bowel syndrome, and vomiting (other than
hairballs) among cats that I have seen in the past two years. All had
one thing in common... a clumping product in their litter box. In
several cases, simply removing the litter improved the condition of
the cat. After a period of natural cleansing, with herbs and
homeopathy, cats with "irritable bowel syndromes" (which had been
unsuccessfully treated by veterinarians with a variety of medications)
passed copious amounts of a gel-like substance, which prompted me to
study these clumping litters. I found that when mixed with a small
amount of water it maintained it shape, but turned to a gel after
repeated contact (60 to 72 hours) or with additional fluid added (as
would be found in the digestive tract). One can only imagine what
happens when this substance is inhaled! One thing for sure, cats
ingest or inhale this substance each time they visit their box and
when cleaning themselves afterwards."
Great clumping cat litter...Is that why Kitty is so sick?!
"The chronic ingestion of bentonite-containing cat litter by this cat
appeared associated with hypokalemia, lethargy and muscle weakness,
dehydration and heart murmur in addition to macrocytic hypochromic
anemia. Clinical signs quickly resolved with administration of fluids
and whole blood and removal from the cat litter.
In vitro experiments have confirmed that bentonite clays adsorb
potassium (1-3), and it has been speculated that the presence of
bentonite in the gut may inhibit the absorption of dietary iron (5)."
Suspected Bentonite Toxicosis in a Cat from Ingestion of Clay Cat Litter
Originally published in the Journal of Veterinary and Human
Toxicology, Vol. 38, No. 6, October 1996 (Fred Oehme, DVM, editor)
"The arguments for potential hazards to pets of using clumping clay
with sodium bentonite certainly sound logical:
* Cats inhale dust from clay litter, or ingest it while cleaning their
feet. Kittens, being curious creatures, sometimes eat litter.
* The powerful clumping abilities of sodium betonite cause the
ingested clay dust and particles which, when combined with natural and
ingested liquid form a solid mass. (When liquid is added, bentonite
swells to approximately 15 times its original volume, as quoted from
Cat Fancy magazine in the McInnis article.)
* Inhaled particles could cause similar problems in the moist climate
of the lungs. (The dust in clay is silica dust, which is not
particularly friendly to either human or feline lungs.)
* The "clumping activity" in the intestines could draw fluid out of
the body, causing dehydration, and possibly consequential urinary
* The clumping substance coats the digestive tract,"attracting the
collection of old fecal material, increasing toxicity, bacteria growth
and prohibiting proper assimilation of digested food. This can lead to
stress on the immune system, leaving the animal susceptible to viral,
bacterial, parasitic and yeast infections." (From an article by Lisa
* The problems can also extend to dogs, who sometimes are inexplicably
drawn to "litter box snacks."
Absent any scientific studies or documented cases, it is hard to make
an objective decision about the use of clumping clay litters for our
cats. However, since there are a number of alternative litters that do
not use sodium bentonite, the prudent cat caregiver would consider
using one of those as an alternative.
The Rise and Fall of Clumping Clay Litter (beware the ugly, flashing ad!)
On the other side of the debate:
"Are clumping litters safe for my cat?
Yes. 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 23
years as a feline only veterinarian, he has never had a case where
clumping litters have caused a problem with a cat."
Precious Cat FAQ
" Is Clumping Cat Litter safe for my cat's health?
Yes. It's safe! As a major manufacturer of cat litter, we go to
significant lengths to assure that our products are safe for both the
consumer and the end user, your cat. We are aware of the concern about
the safety of clumping cat litter expressed recently in a holistic
magazine. The article suggested that clay litter was the cause of
death in some kittens. However, after review, it is evident that there
was NO post-mortem, NO histopathology findings, or any other
scientific data presented, linking clumping litter with problems
observed in the felines. Our research has also produced NO link that
clumping litter is harmful to cats. As always, we will continue to 'go
that extra mile' to offer you safe and effective products.
Is Clumping Litter dust harmful?
No. Clay dust is not harmful to you or your cat! A 1992-1994 study
conducted by the TRC Environmental Corporation states that the amount
of dust in clumping litter is well below harmful levels. Simplicity
PlusŪ Clumping Cat Litter is made from Natural clay and is 99% Dust
Simplicty Plus FAQ
"Some owners have voiced concerns to CATNIP about kittens ingesting
clumping litter. Is clumping litter safe for kittens? At present,
nothing in the scientific literature suggests problems for kittens
that ingest clumping litter. On the other hand, Dr. Amy Marder, animal
behaviorist and clinical assistant professor at Tufts University
School of Veterinary Medicine, has heard stories from veterinarians
and veterinary technicians about cases where (they believe) clumping
litter caused a problem. ?But these cases are rare and anecdotal,?
says Dr. Marder. ?No one has collected the data.?
Although there is no proven relationship between ingestion of clumping
litter and gastrointestinal upsets, we recommend keeping a watchful
eye on kittens. given that kittens are curious and adventurous, you
have to expect that when you plunk them down in any litter for the
first time, they may test it out. Some may taste the new ?stuff? to
find out whether it?s food, and some may play in it. Certainly, as
with any kitten ?first,? you need to be available to supervise and
help a kitten understand what it?s meant to do in a litter box."
Kittens and Clumping Litter
"SMI even spoke to the holistic veterinary practitioner who first
raised this litter issue and she was not able to provide a single
piece of evidence linking clumping litter with sickness or death. Even
the ASPCA has no health issue with clumping cat litter and they
continue to recommend it.
Despite numerous consultations, interviews and tests, neither Clorox,
SMI nor any of the veterinarians with whom we have spoken, have been
able to find any scientific evidence linking the use of clumping
litter with the sickness or death of any kitten or cat."
"The primary ingredients in ARM & HAMMER Super Scoop are high-grade
sodium bentonite, a special type of natural clay, and the world's most
proven deodorizer, genuine ARM & HAMMERŪ Baking Soda. An additional
ingredient is added to ensure the odor-controlling ingredients are
evenly distributed. The last ingredient, a moisture-activated
fragrance, is found only in the Fresh Clean Scent variety. Super Scoop
has been carefully evaluated and determined to be safe for both you
and your feline."
Arm & Hammer Super Scoop FAQ
"While rumors have suggested that scoopable litters can cause health
problems in cats, we are unaware of any actual incidents. Often cats
that are sick will eat their litter. Pet owners will sometimes see
this and attribute the illness to consumption of the litter, when in
fact eating the litter could be a symptom of an existing illness.
We surveyed hundreds of vets and consulted with our own veterinary
advisor, and none of these medical practitioners had encountered a
case involving digestive problems caused by scoopable litters. To our
knowledge, there is no research that indicates scoopable litter causes
any health problems."
Cat's Pride FAQ
Absent clear scientific evidence, those bound to feline service should
exercise caution when choosing a litter, and may do well to consider
litter that does not contain Sodium Bentonite.
Hope this helps!
--Missy <-- owned by two cats
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