Why Is My Cat Eating Litter?

While cats engage in a variety of odd—but normal—behaviors, eating their litter is not one of them. Here’s why a cat might start eating their litter and what you should do.

Why Do Some Cats Eat Litter?

The repeated abnormal ingestion of substances not normally eaten is a health condition known as pica. This may be why your cat is eating their litter.

With pica in cats, it’s important to investigate whether there’s an underlying medical issue causing the behavior. Acute (sudden onset) pica usually has a medical condition causing it, and chronic pica might be related to medical issues or secondary to self-soothing or obsessive-compulsive behavior.

Aside from pica, there are many other underlying reasons that a cat may ingest cat litter, including:

• Curiosity: Many kittens will play with cat litter just as they play with toys. They can even ingest the litter during play, and this can become a problem if it becomes impacted in their gastrointestinal tract.

• Scent: Litter made from food-based products such as corn, walnut shells, wheat, or grass can be enticing to cats because of its scent.

• Anemia: Cats with anemia have too few red blood cells in the body. Red blood cells act as oxygen transporters to other body cells performing daily functions. Without these oxygen-carrying red blood cells, cats become lethargic and have pale gums.

  • Anemia can be caused by many underlying medical issues, including toxins (such as lilies and Tylenol), kidney failure, viruses such as feline leukemia (FeLV) and feline immunodeficiency virus (FIV), blood-borne parasites (such as mycoplasma), severe flea infestation, and/or certain types of cancers.

• Dietary deficiencies: Cats need certain nutrients in their diet to grow and thrive. Failing to provide these nutrients can cause your cat to search out other things to fill their stomach—including cat litter. It’s important to have your cat on a life-stage appropriate, well-balanced food to support their health. Your vet can help you choose the best cat food.

• Intestinal parasites: Worms and other parasites, such as coccidia and giardia, have led to pica in cats. While the connection isn’t clear, this is believed to be related to a persistent state of hunger and the idea of dislodging worms from the cat’s gastrointestinal tract.

• Hyperthyroidism: Rarely, this medical condition can lead to pica due to the high levels of thyroid hormone, which can cause an increased metabolism and excessive appetite.

• Brain tumors: Dependent on the location of the tumor, masses can cause pressure on certain areas of the brain, which can lead to increased hunger and the eating of foreign material.

• Coprophagia: Defined as eating feces, this is a common behavior seen in younger cats. This is usually secondary to curiosity but can also be due any of the medical issues listed above, most commonly intestinal parasites. Appropriate diagnosis and treatment can help reduce this behavior.

• Boredom/stress: When cats become bored or have anxiety, they can react by ingesting cat litter. Keeping stress to a minimum and keeping your cat entertained with safe cat toys and daily playtime can help eliminate this behavior.

Is Litter Toxic to Cats?

There are several different types of cat litter. Some are toxic when eaten, especially if ingested in large amounts or ingested chronically over long periods of time.

Signs of litter toxicity include:

• Nausea

• Lack of appetite

• Vomiting

• Diarrhea

• Lethargy

• Weakness

• Coughing

• Trouble breathing

• Wheezing

Clumping Clay Litter

Clumping clay litter has been linked to vomiting, diarrhea, gastrointestinal obstruction, and respiratory problems when eaten by cats. Eating this litter can form a cement-like concretion of material in the stomach, leading to an intestinal blockage. Surgical removal of this obstruction is sometimes necessary. 

Some types of litter, including clay, can also create a dust cloud when poured or scratched at. This dust can be inhaled or licked off the paws when cats clean themselves. The dust inhaled can coat the lungs and airways, leading to respiratory issues. Licking causes the dust to coat the gastrointestinal tract, leading to stomach upset.

Crystal (Silica) Litter

Another popular type of litter, crystal litter can also cause safety issues in cats.

This type of litter is made of silica gel (silica dioxide and water). The clumping formulation of this type of litter runs the same risk of gastrointestinal issues as clay litter does, including blockage.

Corn, Walnut, and Wheat Litters

Corn, walnut, and wheat cat litters are great biodegradable cat litter options. However, they do carry a risk of fungus growth (specifically aflatoxin mold on corn). While this isn’t common, it can be extremely toxic—even fatal—to animals if it does occur.

Clinical signs of this toxicity include vomiting, diarrhea, lethargy, not eating, and jaundice. Walnut and wheat litter can also be quite dusty, leading to respiratory issues or stomach upset if too much of the dust or product is ingested.

Paper and Wood Litters

Paper- and wood-based litter are another biodegradable and environmentally friendly type of cat litter. They are low in dust, scent-free, and highly absorbent. The litter is not considered toxic if ingested; however, if ingested in large amounts, it can still cause stomach upset or blockage.

What To Do if Your Cat Eats Litter

Most litter ingestion occurs in small amounts and will cause no side effects to your kitty. But it’s important to monitor your cat to prevent litter ingestion, especially if your cat is young or has medical issues that can lead to pica, such as intestinal parasites or anemia. 

If you notice your cat is eating litter persistently, or if your cat stops eating and shows symptoms of vomiting, diarrhea, constipation, coughing, wheezing, or lethargy, take them to the vet.

What Can Veterinarians Do for Cats Who Eat Litter?

Your veterinarian will take a detailed history of your cat’s lifestyle, home environment, and clinical signs leading up to the veterinary visit. They’ll perform a thorough physical examination to assess your cat’s hydration, heart rate, respiratory rate, lung sounds, and any stomach pain.

Tests may be performed, including:

• Blood work to assess for any systemic disease processes

• A fecal test to assess for intestinal parasites

• Abdominal imaging (most commonly with radiographs) to assess for litter blockages

Treatment may be as simple as outpatient therapy with anti-nausea and vomiting medications and fluid therapy. In more severe instances, hospitalization and even surgical removal of a blockage may be necessary.

Appropriate treatment of any underlying disease process may also be necessary to eliminate the litter-eating behavior. This includes stimulating the cat’s environment  if the litter eating is considered secondary to compulsion or boredom.

How To Prevent Your Cat From Eating Litter

There are multiple ways to help prevent your cat from eating litter, including:

• Scooping the box at least once daily and cleaning litter that has fallen around the box

• Cleaning out the entire litter box with soap and water every week, then replacing with fresh litter

• Feeding your cat a well-balanced, high-quality commercial cat food to avoid vitamin and mineral deficiencies

• Taking your cat for annual or biannual health examinations by your veterinarian, based on their age and health. These can help diagnose underlying medical conditions early and, even better, can help prevent some of these issues.

• Improving your cat’s environment with toys and cat furniture 

• Keeping stress to a minimum
• Monitoring your cat’s litter box practices closely. Consider changing the litter if you notice ingestion. It can be helpful to discuss these options with your veterinarian to help lessen this behavior.