Why do cats eat or chew paper and cardboard?

Look closely at this picture of S’mores. What do you see?

I see teeth marks.

If you have a cat who loves to chew, lick, nibble, or gnaw on paper and cardboard, you probably have teeth marks in more than a few items around your home.

And you’re not the only one. Questions about cats and cardboard regularly make the rounds of cat forums. Some cat guardians share that their cats are connoisseurs of particular varieties of cardboard and paper. One cat likes to chew on nothing but diaper boxes. Another loves only paper towels. And still another prefers paperback books.

But why do so many cats – who are supposed to be obligate carnivores, who eat only meat – seem to want to chow down on cardboard and paper? Is it a dangerous habit? What should you do about it?

Five reasons why cats chew or eat paper and cardboard

Some cats have an urge to eat things they shouldn’t

“Pica” is the term for this behavior, and it’s not limited to cats. Humans and other animals can suffer from pica, too.

Pica is the compulsion to eat non-food items. Cats are known for not only eating paper and cardboard, but for eating plastic, cat litter, wool, and other items that have absolutely zero nutritional value.

There are three things that can cause a cat to participate in pica behaviors: genetics, health issues, and life circumstances.

Certain cat breeds, including Oriental Shorthairs, Burmese, Birman, and Siamese cats, have a greater tendency to eat non-food items. This suggests that genetics play a role in the likelihood that a cat will have pica.[1][2]

Certain health issues seem to be associated with pica, too. There’s a correlation between pica in cats and feline leukemia, feline immunodeficiency virus, diabetes, and brain tumors. Cats with intestinal parasites, inflammatory bowel disease, or even an intestinal blockage can show signs of pica.[3]

And pica can just be a cat’s way of dealing with something else that is going on in her life at the moment, including any of the other four conditions below.

(Read, “Why do cats chew on plastic?” for more information about this related topic.)

Cats may chew cardboard and paper when they are bored or stressed

(*Note: as an Amazon and Chewy affiliate, I earn from qualifying purchases.)

Do you bite your nails? Tap your foot compulsively? Smoke? Eat when you’re not hungry? You’re not the only one.

Boredom, stress, and frustration can cause anyone to seek ways to relieve those unpleasant emotions, whether cat or human.

Boredom and cats do not mix. Cats are curious, intelligent creatures who need an outlet for all that brain power. It's important for them to live interesting, stimulating lives that allow them to be their full cat selves.

When we bring a cat into our lives, it is incumbent upon us to meet all his needs. Among other things, we are responsible for creating an enriched home environment. When a cats’ physical and intellectual needs aren't met, he may turn to damaging compulsive behaviors to deal with his own frustration.

For enrichment, provide your cat with a wide variety of toys that have different textures or produce different sounds, from crinkle balls to this bird that chirps. Provide puzzle toys that force her to plan and think. Give her silvervine sticks to chew on, and a fun window seat from which to view the world. Take toys and games in and out of circulation so there is always something "new" for your cat to explore.

Stress can also underlie pica behaviors. Look at the level of stress in your household from your cat’s point of view. Has there been a change in dynamic or routine that could be causing anxiety? Have you recently returned to working in the office (or conversely, just begun working from home)? Have you moved recently, or changed anything in your house, from new furniture to new paint?

Are there any new family members, pet or human, that could cause your cat to feel anxious? Have there been any losses, such as a death in the family, or even a child leaving for college?

And how about the other relationships in the household? In a multi-cat household, are all the cats on good terms? Is there an ongoing feud with the dog?

These related posts might provide insight: 

Do cats get jealous?

Can cats and dogs get along?

How to introduce a new cat to your cat

Separation anxiety in cats

How do cats deal with a change in routine?

We can’t always change things back to the way they were to make life less stressful for our cats (you’re not giving the new baby back, are you?) but if we try to recognize the source of a cat’s behavior, we can take steps to help ameliorate the stress.

Cats chew cardboard and paper because they don’t get to hunt (maybe)

Until our cats start talking to us in full sentences, we may never know the real motivation for their behaviors. Sometimes, the best we can do is observe and try to draw conclusions based on what we witness, but that is an inexact science at best.

One thought is that cats shred cardboard to indulge their instinct to shred prey.

Cats are carnivores. They're not nibbling at the corners of scones for lunch; they eat other animals, which don’t necessarily come bite-sized. How do cats turn larger prey into a meal they can swallow?

Big cats, like lions, shred their prey with specially designed teeth, including canines for tearing and carnassial teeth for slicing their meat as with scissors.[4]

Housecats, too, have teeth that differ from  those of other meateaters. Dogs and humans have molars to grind food.[5] Cats, both house and big, don't grind their food; they shred until the pieces are small enough to swallow.

We know that housecats, who may get their food from a can, delivered to them in a pretty cut-glass bowl, still need to act out the hunt. Even though they don’t need to hunt, cats need to hunt.

Do some cats also need to act out the aftermath of the hunt? Do they have an urge to tear and shred something, even if they have no intention of actually eating it?

It’s possible, even if there is no scientific research that supports this idea yet.

Some cats chew on paper and cardboard because they have dental disease

Dental disease is, unfortunately, common in cats. Some 50-90% of cats past the age of four suffer from it. Discomfort in the mouth could cause a cat to gnaw on non-food items, like cardboard, in an attempt to relieve the pain.

The three most common mouth issues in cats are gingivitis, periodontitis, and tooth resorption.

Gingivitis is a fancy word for inflammation of the gums. Plaque, a film on the teeth, builds up. The bacteria that live in the plaque, causing no trouble at all at first, eventually find their way underneath the gums. A cat’s immune system responds to this invasion with redness and swelling.

Cats who suffer from gingivitis may not want to eat, may turn their heads while eating, drool, or have bad breath. Fortunately, there are treatments for gingivitis – your vet will recommend a course of action depending upon the severity of your cat’s disease.

Periodontitis occurs when gingivitis is not properly addressed. The bacteria that prompt gingivitis cause the tissues that connect the teeth to the jaw to break down. In extreme cases of periodontitis, a cat may have to have the loosened teeth extracted.

In tooth resorption, the tooth spontaneously starts to break down. We don’t know why it happens, but it’s the most common cause of tooth loss in cats.[6]

What these three common conditions have in common is extreme discomfort on the part of your cat. If cardboard-chewing is a new behavior for your cat, and if she is exhibiting any other signs of mouth pain, have her seen by a vet.

Your cat chews cardboard because he is a kitten

Kittens, like humans, are born toothless. But unlike humans, who only teethe once, kittens teethe twice in their lifetimes.

A kitten's first baby teeth are called deciduous teeth, or milk teeth. They appear sometime after a kitten turns two weeks old, but before she is a month.

Eventually, the milk teeth fall out to make way for a kitten’s permanent adult teeth, at around three-and-a-half to four months old.

Teething can be uncomfortable for kittens. There is pressure from the emerging teeth and the gums may be sore. You might see blood on objects your kitten chews or specks of blood in the food or water bowl. Your kitten may not allow you to pet his face and he may temporarily lose his appetite.[7]

You can offer your kitten a teething toy, but be careful. Some toys intended for chewing are actually too hard for cats and can cause broken teeth. Toys that are too soft (and invite vigorous chewing) can break apart and be swallowed. If you decide to try a teething toy, like this dental ring by Petstages, supervise your kitten while she is using it. Take it away again when you can no longer keep a close eye on her.

Is it safe for a cat to eat paper or cardboard?

There are two risks to be concerned about if your cat likes to munch on cardboard or paper products: the formation of a blockage in her digestive tract, and the potential toxicity of the paper products themselves.

Gastrointestinal blockage. If you’ve ever seen what happens when you get a wad of paper towels wet, or have seen what happens to your newspaper if it’s left at the end of the driveway in the rain, you’ll understand what happens to paper and cardboard in your cat’s digestive system.

A cat can pass a small amount of paper through her intestines. But too much can clump together and get stuck. Anything stuck in the digestive tract is called an obstruction or foreign body and often requires immediate, life-saving veterinary intervention.

If you suspect your cat may have consumed more than a little paper or cardboard, and if he is showing any of the symptoms below, contact a veterinarian immediately. A blockage could cut off the blood supply to the bowels, and, untreated, lead to death. The wadded paper product will likely need to be removed by surgery.[8]

Signs your cat may be suffering from a foreign body:

• Vomiting
• Weakness or lethargy
• Diarrhea
• Loss of appetite
• Drooling
• Your cat is “not himself” or behaving uncharacteristically aggressively[9]

Paper products may be toxic. Paper and cardboard may start out as a natural product, but there’s a very long road from tree to cereal box. The paper production process requires the addition of dangerous chemicals to bleach the wood pulp, and give the paper certain qualities, such as strength and durability, or to produce a particular kind of writing surface.[10]

These chemicals are not the kinds of things that belong in the body of any cat. And while it’s not likely that your cat will ever ingest enough to be toxic, it’s something to think about if you have a cat who really loves to nibble on paper or cardboard.

Should I remove all the cardboard boxes from my home?

The kind of cat who will compulsively eat - actually consume - paper and cardboard should not have access to these products. The risk of an obstruction is too great.

Most cats, on the other hand, actually benefit from access to a cardboard box. There is some serious science that supports the idea that cats need access to a cardboard box to be happy. Read about the science behind cats’ obsession with cardboard boxes here.

If you keep cardboard boxes in your home for your cat, be thoughtful about what you choose. Consider where they came from, and the kinds of inks that they are imprinted with. Watch your cat with a new box at first, and then again if you notice any changes in your cat’s behavior. A cat who never chewed cardboard before, who suddenly starts, is one to be concerned about. 

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Dawn LaFontaine is a lifelong animal lover who always seems to have a little pet hair in her keyboard. Her blog, Kitty Contemplations, helps cat guardians better understand and care for the special beings they share their lives and homes with. Her cat-products business, Cat in the Box, sells beautiful, well-made, and award-winning products that she designed to meet the biological needs of cats.

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FOOTNOTES

[1] Radosta, Lisa. “Why Does My Cat Eat Plastic?” Daily Paws, www.dailypaws.com/cats-kittens/behavior/common-cat-behaviors/why-do-cats-eat-plastic.

[2] "Pica in Cats." International Cat Care, 6 Oct. 2019, https://icatcare.org/advice/pica-in-cats/.

[3] Fries, Wendy C. “Strange Things Cats Eat: Pica Symptoms and Treatments.” WebMD, WebMD, 21 Apr. 2012, pets.webmd.com/cats/guide/unusual-cat-cravings#1.

[4] “Let's Look at Lions - Learn about the African Lion.” ALERT, 10 Jan. 2020, k https://lionalert.org/lets-look-at-lions/. 

[5] Rouge, Melissa. “VIVO Pathophysiology.” Dental Anatomy of Cats, http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/catpage.html.

[6] “Feline Dental Disease.” Cornell University College of Veterinary Medicine, 3 May 2019, https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-dental-disease

[7] “Kitten Teething.” Greencross Vets, https://www.greencrossvets.com.au/services/kitten-teething/.

[8] “Intestinal Obstruction in Cats.” PetMD, PetMD, 17 Mar. 2016, https://www.petmd.com/cat/conditions/digestive/c_ct_gastrointestinal_obstruction.

[9] “Intestinal Blockage.” Berkley Dog and Cat Hospital. Berkeley Vet Blog, https://www.berkeleydogandcat.com/site/blog/2021/10/14/cat-intestinal-blockage.

[10] “Pulp and Paper Manufacturing Process in the Paper Industry.” Pulp and Paper Technology, 8 Feb. 2022, https://www.pulpandpaper-technology.com/articles/pulp-and-paper-manufacturing-process-in-the-paper-industry.