Cat Litter Box Issues


Cats are highly adaptable indoor-animals and take instinctively to using a litter box for their toilet needs. One aspect of their instinctual behavior is to dig a small pit and then cover over with some of the litter their urine or feces afterwards. Some cats do this intermittently, some never. Either way, a box already soiled in several places will make it more difficult for naturally fastidious cats to dig a pit without dirtying their paws. One regular litterbox for one adult cat should, therefore, be cleaned out at least twice a day, and the stools looked at to check for diarrhea or constipation.

The latter condition, along with anal gland issues and lower urinary tract inflammation, infection and calculi/stones, can cause pain during evacuation. Getting in and out of the box and positioning to evacuate can be painful for older cats suffering from arthritis in the hips and vertebrae. Pain, and associated fear, is a major reason why cats start evacuating outside of the litter box when being inside it becomes associated with pain. Such house-soiling calls for a veterinary examination especially when other possible causes have been ruled out. These include:

  1. Not cleaning the box out often enough.
  2. A high, highly irritating ammonia content inside a covered box
  3. Not placing the box in a quiet, low traffic area that is easily accessible because many cats do not like to be disturbed and may feel especially vulnerable while in the process of evacuation.
  4. Placing the box close to intermittently activated appliances such as a basement heater.
  5. Placing food and water close to the litter box.
  6. The odor, texture and type of litter may be problematic, leading to litter box aversion because of irritating artificial scents, dust and adherence of material to the paws and rear-end fur.

In her book Shelter Cats ( Howell Books, N.Y., 1998) Karen Commings advises; “Litter boxes should be filled with litter to a depth of about three inches. Some cats prefer not to step on litter or have their feet sink into it when they get into the litter box, however. Using lesser amounts or pouring litter into just one end of the box may satisfy your cat if she has an aversion to getting her feet dirty”. She also notes that some cats seem to prefer two litter boxes for separate functions to have their own box when there are other cats.

Material adhering to the cat after using the box can, in part, be dislodged by having the cat walk on a rough-textured mat in front of the litter box. This will also help stop tracking into the house. One of my concerns is cats swallowing this material along with litter dust when they groom themselves. In rare instances intestinal blockage requiring emergency surgery have been reported.

Volatile organic compounds are used to give cat litter a floral scent is for humans, not for their cats who may develop respiratory problems and allergic reactions especially in combination with a covered litter box. Cedar chip litter has been linked to allergic reactions in cats who develop skin irritation and scratch themselves to the point of self-mutilation if not diagnosed and a different litter used.


Sodium bentonite, silica and other small particle materials in clay litter may lead to respiratory disease since cats do sniff and paw the surface of the litter often for quite some time to find a clear spot to dig before they evacuate. Unlike some other kinds of litter, clay litters involve mining which can be ecologically harmful, do not recycle well and can clog drains.

Some kinds of litter may be contaminated with cancer-causing aflatoxin from moldy corn. The manufacturer of the World’s Best cat litter (made from corn byproduct) informs me that they do test for aflatoxin, but not for glyphosate. This herbicide, widely applied by corn producers, has been designated a probable carcinogen and may play a role in chronic bowel disease. Litters made from wheat byproduct may also be contaminated with mold and agrichemicals.

Manufactured cat litter derived from recycled wood & paper products come from the timber industry that has been a major contaminator of the environment for decades. These products should be dust-free to limit cats’ exposure to dioxins, pesticides, fungicides and other wood preservatives. Natural oils, as from cedar and pine, may cause respiratory tract irritation especially if used in a covered litter box. But they do naturally reduce odor and have antibacterial properties.

According to Ted Mischaikov, CEO of Healthy Pet, “Pulp mills have a variety of pollutants, but our fiber is sourced separate from those distilling/chemical processes and contains only water and minute amounts of white fiber. Specific to our paper pellet cat litter, I also want to stress that there is no post-consumer waste, ink or other contaminants. I am glad and proud that we can help reduce the landfill and/or burning of paper fiber from pulp mills via repurposing into healthy and safe pet products. It take diligence on our part across several dynamics of variability but that is simply a part of embracing a sustainability model”.

Some household cleaning and disinfecting products such as Lysol used in and around the litter box may put cats at risk, most notably Swiffer and other antibacterial cleaners and cationic detergents containing quaternary ammonium compounds which cats can groom off themselves or absorb through their paws after walking and lying on treated surfaces. (See Richard Malik et al Benzalkonium chloride intoxication in cats. Veterinary Record Feb.28: p 226-227, 2015 and Small Animal Toxicology by Michael E. Peterson & Patricia A. Talcott, 3rd edition, Elsevier Health Sciences, 2013).

While some cat litters like those from Healthy Pet can be safely and effectively processed into garden compost, they are generally best disposed of in biodegradable bags placed in with household garbage. Disposal by flushing down the toilet may clog drains and spread disease such as toxoplasmosis which has been linked to often fatal infections in California’s sea otters and other marine mammals. Pregnant women as well as people with impaired immune systems should handle soiled cat litter with caution or have others clean out the litter box because they are especially at risk when cats have this disease which, along with other potential pathogens, is passed out in their excreta.


Often under-diagnosed when cats go blind or develop a fever, become lethargic, anorexic, lameness, skin nodules and respiratory distress, histoplasmosis is a fungal disease in the soil. It is the second most commonly reported fungal infection in cats, following cryptococcosis.

Cryptococcosis is a type of fungal infection that occurs when a cat inhales spores from a type of fungus that grows in organic material such as soil, decaying wood, or bird guano (especially droppings from pigeons). Spores also can enter the skin through an open wound.

Since these fungi are everywhere in the soil, cats are likely to get the soil on their paws and ingest it when grooming, along with fungal spores. The spores could be inhaled or get into the fur in dry and dusty weather and when cats dig into the soil chasing small rodents or making a pit in which to defecate. These fungal diseases are a major reason to keep cats indoors and never use soil in the cat’s litter box.