Is Kitty Litter Dangerous?

Is Kitty Litter Dangerous?

I sometimes worry about breathing in the dust from cat litter. Have there been any studies or are there any health concerns on the danger of breathing in litter dust, either for me or my cats?

You raise an interesting question, but one to which there are no clear answers. I did a medical literature search to see if there were any studies linking inhalation of cat litter dust to any human health problems and found nothing. However, I did come across a controversy about this subject online – whether or not certain cat litters are harmful to humans or cats. The issue under popular debate is the effects of clumping litter – the kind that forms easily removable clumps when cats urinate in their boxes. As far as I can determine, this concern stems from a report by a cat breeder of the death of one or two litters of kittens that she attributed to internal blockages formed from litter dust the kittens inhaled in the box and licked from their fur when they groomed themselves. The litter ingredient blamed for this alleged effect is the clumping agent, sodium bentonite, used in most major brands of clumping clay cat litter. I did find a report published in 1996 in a veterinary journal about a cat that was brought to the vet with lethargy and muscle weakness on two occasions after ingesting litter containing bentonite.

Unfortunately, most reports on this subject are anecdotal. I’ve seen no studies suggesting that clay litters containing sodium bentonite put either cats or humans at increased risk of any health problems. Given the fact that the number of pet cats in the United States is upwards of 90 million, if litter dust were harmful, you would think that vets would have been seeing more sick cats with illness attributable to the dust and that the litter issue would have been scientifically investigated.

If you’re concerned about the dust thrown up by clay litters, you can switch to a litter made of wheat or corn – these contain no sodium bentonite. While they’re more expensive than clay litter, they last longer and have similar clumping properties. When disposing of used litter of any type, you can reduce your own exposure to dust by slipping the litter box into a large plastic bag before up-ending it. And since litter typically throws off dust when poured into the box, avert your head (or wear a mask) when filling the pan.

Is Cat Litter Dangerous for Humans?

Have you ever changed the litter box and wondered if inhaling that dust is unhealthy? Curious cat owners want to know – is cat litter dangerous for humans.

Intestinal Issues:

This can be caused by parasites and bacterial infections that the cat might be carrying and they can found in the cats feces. Exposure to these parasites, roundworms and bacterial infections can come for direct contact with the feces or from the soiled and contaminated litter.

Asthma and Allergies:

Jim Hanophy, CEO of Operation Kindness, the oldest and largest no-kill animal shelter in North Texas says, “Generally, most cat litter products are safe.  However, if the litter has clay or perfume, some people could be allergic to those components. Sometimes, cats can be allergic to them too.” When changing the litter box if you use the traditional clay you will notice a lot of dust rising up from the box. This happens when your cat uses the litter box and scratches the litter. There are reputable anecdotal pieces of evidence of cat owners having severe asthma attacks after this, though not a lot of scientific studies. Not only can you generate a severe asthma attack from the dust from the cat litter you use, so can your cat. Keeping the litter box clean helps, but it is the type of litter you use that really makes the difference.

How to Avoid Asthma Attacks, Allergies and Intestinal Issues from Cat Litter:

It’s all about the type of cat litter you choose. Hanophy advises, “Check ingredients. Also, there are hypoallergenic litters made for cats. “Yesterday’s News” is made from paper.  There are also other brands that reduce allergens.” Buy cat litter that is fragrance free, scoopable, biodegradable, flushable, and not clay-based. Avoid clay-based litter, pine litter and sawdust-based cat litter. Don’t trust the brands that promise to be free of dust – they might be –  but they also contain chemicals that might be cancer causing according to the International Agency for Research on Cancer. The particles in this litter get into your cat’s fur and on her paws and then tracked around the house where humans can become exposed. In addition to the cancer risk there is a much milder risk of respiratory infections. If you have intense asthma, respiratory infections can be particularly dangerous.


This is the major danger to humans from litter boxes and cats in general. Toxoplasmosis is caused by a parasite in the cat feces. It can also be caused by any fecal contamination or by exposure to some raw meats such as lamb. It is estimated that up to one third of the world’s population carry the toxoplasma infection and parasite. It is one of the most common parasites in the world. It is often found in cat feces and so the litter box is a definite area of exposure. This is not a fatal disease for most people. Most people will not have much problems with toxoplasmosis, but it can cause flu-like symptoms and an extreme fatigue. Most people will never know they are carrying it because they will have no symptoms.

For pregnant woman and anyone with a compromised immune system, the toxoplasma parasite can cause all kinds of issues and diseases not the least of which is encephalitis, issues with the eyes, inner ears, liver and heart, and neurological diseases. It has also been linked in recent studies to psychological disorders such as ADHD, OCD, and schizophrenia. There is also a link to suicidal behavior.

Which Cat Litter Is Best for Your Pet?

There are a lot of different types of cat litter on the market. All of which are basically safe for healthy people.  Those who have compromised immune systems and pregnant women need to avoid the chore of changing the cat box. Avoid the pine, sawdust and clay. Stick to cat litter that’s scoopable, fragrance-free, flushable, and biodegradable. Use quart-sized zippered plastic bags to bag up the clumped urine and feces you scoop up and zip it closed. Wash your hands thoroughly after changing your cat’s litter.  

Is cat poop dangerous?

Cat poop could be a “vast and underappreciated” public health problem, according to Drs. E. Fuller Torrey and Robert H. Yolken.
The pair on Tuesday published a paper on the dangers of Toxoplasma oocysts, which are found in cat poop, in the journal Trends in Parasitology.
In the journal article, Torrey and Yolken call for better control of the feral cat population and more research on the parasites. In the meantime, CNN asked the doctors how we can keep our families safe. Torrey and Yolken responded to the questions via e-mail.
CNN: We’ve heard that cat poop can be dangerous for pregnant women. Should other people be wary, too?
Drs. E. Fuller Torrey and Robert H. Yolken: It is true that some cat poop contains Toxoplasma gondii, a parasite for which cats and other felines are the definitive host. This parasite can affect the fetus if a woman becomes infected while pregnant. That is why pregnant women are warned against changing cat litter. It’s also well-known that Toxoplasma gondii can cause major brain infections in individuals with AIDS and other conditions associated with immune deficiency.
So what’s new? Recent studies suggest that individuals with disorders such as schizophrenia, obsessive-compulsive disorder, rheumatoid arthritis or brain tumors are more likely to have Toxoplasma gondii antibodies than other people. There are also suggestions that Toxoplasma gondii can affect memory and other cognitive function in people who are not otherwise ill. In no way have we established Toxoplasma gondii as a cause of these disorders, but it has led us to rethink the possible risks of cat poop.
CNN: How big of a risk are we talking about?
Torrey and Yolken: There are an estimated 82 million owned cats and another 25 million to 60 million feral cats in the United States, and their numbers have increased markedly in recent years. Based on studies done in California, it is estimated that these cats deposit 1.2 million tons of cat poop into the environment each year. At any given time, approximately 1% of cats are infected with Toxoplasma gondii.
The infective form of Toxoplasma gondii deposited in cat poop are called oocysts; a single infected cat can deposit millions of oocysts, each of which may survive in moist soil for 18 months or longer. It’s thought that it only takes one oocyst to infect a human, which is concerning.
CNN: So what can people do to protect themselves?
Torrey and Yolken: It is important to note that cats that are always kept indoors are usually not a problem. Almost all cats that become infected, and thus deposit infective oocysts, are outdoor cats. Keep in mind cats are no respecters of property lines so a neighbor’s cat could deposit Toxoplasma gondii oocysts in your garden or children’s play areas.
Weird science: Kitty litter increases risk of suicide?
To stay safe, follow these suggestions:
• Cat litter should be properly disposed of in the garbage, not flushed down the toilet where it can enter rivers and lakes.
• Children’s sandboxes and play areas should be covered when not in use. Cats selectively relieve themselves in areas with loose soil or sand. In the studies we reviewed, we found very high concentrations of Toxoplasma gondii oocysts in these areas. If a sandbox has not been covered, the sand should be replaced and then kept covered.
• Gardeners should wear gloves since gardens are another favorite place for cats to relieve themselves. One study reported that gardeners may have as many as 100 oocysts in dirt under their fingernails.
• Vegetables from gardens should be thoroughly washed.

Are the Fumes From Litter Boxes Toxic to Humans?

It’s the least favorite job in the house, but you scoop the litter box as an act of friendship for the feline love of your life. There were times when you jokingly thought the fumes to be toxic. There is some truth to that, so it’s best to know the facts.


Toxoplasmosis is the illness that is most commonly associated with the litter box. It’s a parasitic infection that is almost symptomless and when it does occur, it can be mistaken for a mild flu with a fever, muscle aches and swollen glands. Cats can become carriers by eating birds or rodents infected with the parasite and then pass it onto their human companions through contact with the litter box contents. If you’ve been maintaining litter boxes for your cats for years, you may have already been infected at some point. If so, the good news is that you will have an immunity to toxoplasmosis and it should not be a cause for concern for pregnancy or your health in the future.


The ammonia in cat urine can be strong to the point of causing watering in the eyes and headaches. The Center for Disease Control also lists the dangers of exposure to ammonia to include breathing difficulties.

E. Coli

The Escherichia coli bacterium doesn’t typically bring to mind a cat box, but E. coli is present in the intestines of cats as well as in humans. In most instances, the bacteria is harmless, but it can bring on illness, triggering diarrhea and stomach cramps and can be dangerous in severe cases.

Best Practices

Scoop out the litter box once a day and empty and clean it with disinfectant on a regular basis to eliminate or reduce the possibility of reactions and disease. Always wash your hands thoroughly with soap and warm water immediately after working with the litter box. You can opt to wear a mask and rubber gloves to further protect yourself. If toxoplasmosis is a concern, have your doctor perform a blood test to see if you have already been exposed to it. If you have not had toxoplasmosis prior to becoming pregnant, you should avoid cleaning the litter box during your pregnancy.


One of the biggest dangers to a cats health and a dogs (some dogs ingest kitty litter as those with cat/dog households know) is “Litter Box Fillers”.  Cats, Rabbits, Ferrets and even some apartment dogs are litter box trained. What is not known by many are the dangers certain litter poses to pets and humans alike. If you have a multi-mixed pet household of cats and dogs you must read this. As your dog sometimes will delve into that litter box as you know – look what your pets are ingesting.  Here is a copy of an article by Marina Michaels.  We thank her for allowing us to share her research.

Clumping Clay Kitty Litters: A Deadly Convenience?

Clumping clay kitty litters may be related to a wide variety of seemingly unrelated cat health problems, included diarrhea, frothy yellow vomiting, mega-bowel syndrome, irritable bowel syndrome, kidney problems, respiratory problems, general failure to thrive, anemia, lethargy, and even death.   Clumping litter is designed to form a hard, insoluble mass when it gets wet. It also produces a fine dust when stirred (as when a cat scratches around to bury a recent deposit). And these clumping litters absorb many times their weight in fluids. When cats or kittens use the litter box, they lick themselves clean; anything their tongues encounter gets ingested. Kittens especially tend to ingest a lot of litter when they are first learning to use the box. Once the litter is inside a kitten or cat, it expands, forming a mass and coating the interior-thus, both causing dehydration by drawing fluids out of the cat or kitten, and compounding the problem by preventing any absorption of nutrients or fluids.   “There has been a rise in depressed immune systems, respiratory distress, irritable bowel syndrome, and vomiting (other than hair balls) 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.” (“Great Clumping Cat Litter–Is That Why Kitty is So Sick?” Lisa Newman, Healthy Pets–Naturally, April 1994.)

The problem of health difficulties and even deaths resulting from clumping litters appears to be more prevalent than most people are aware of. I recently spoke with another Japanese Bobtail breeder, who told me of a kitten she sold that subsequently became very ill with a severe respiratory problem. The new owner used a clumping litter, and her veterinarian found that the kitten’s lungs were coated with dust from the litter.   For a veterinarian to spot this problem is unusual. A more common diagnosis would lay the blame at the door of a virus, germ, fungus or parasite. There is not a general awareness yet that the clumping litters can be harmful–even fatal–to cats.


And the problem extends beyond cats. As Lisa Newman points out in her article, dogs get into the litter box for “snacks,” and ingest the litter too. She reports that the autopsy of one dog revealed that his stomach was filled with the clumping 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.


You may feel as horrified as I do at the thought that there must be thousands of kittens and cats (and other animals) ailing or even dying from clumping clay litters. What can we do to prevent such suffering?   One thing is let the manufacturers know we won’t buy such products. My husband called a company that makes one of these clumping litters. The woman he spoke with said that the company is aware that clumping litters may be causing health problems, but that it is the consumer’s responsibility to make sure their cats don’t eat the stuff.   My husband pointed out that cats clean themselves with their mouths, so of course they’re going to eat the litter every time they use their cat boxes. Unfortunately, the company’s representative maintained her “buyer beware” position.

Given the attitudes of such companies, we can vote with our pocketbooks by purchasing products from businesses that are more responsive to our concerns. Be sure to let the makers of the clumping litter know why you no longer purchase their product. You might even choose to boycott all products made by these companies (it isn’t hard to find out who makes what–just read the labels). An even more effective move might be to show this article to the owners or managers of stores selling these products.   If you suspect that an animal may be suffering an ailment caused by clumping litter, take him or her to a veterinarian or holistic practitioner immediately, and explain what you think may be happening. If you encounter resistance, it may mean that the veterinarian is unfamiliar with the problem and doesn’t know how to handle it.

Try to find a holistic vet–either locally or someone you can work with by phone–who has some experience with clumping litter impacting the intestines. Most importantly, replace the clumping litter right away with one of the plant-based alternatives. Even if your cat is healthy, it makes sense to switch to a different litter.   If you love cats as I do, spread the word. Tell everyone you know about this problem. Tell your veterinarian. You may save the lives of many kittens, cats, and other beloved creatures.   So what do you use? There are many alternative. A favorite for me is PAPURR. It’s flushable, Kills odors, and just like regular litter only dust free. Even clumps pretty well! Cedar chips are great for cats but not dogs or bunnies. For an all around SAFE choice It is best to stick with paper-type, wheat, corn based litter such as Papurr, Carefresh®, Cat Country, Yesterday’s News, S’Wheat etc….Cedar is very good for cat only house holds but not around dogs. Remember to research what you pet uses in all areas. Not just what it eats!

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