Stefanie Schwartz, DVM, MSc, DACVB


The popularity of cats as indoor pets is largely due to the invention of the litter box in the 1950’s. Domestic cats, descendants of a small wild cat native to northern Africa (Felis lybica), naturally eliminate in loose soil or sand and mark vertical targets like a tree trunk. When you to stop to think about it, it’s really not normal for cats to use litter boxes at all. Cats who choose to void in litter boxes are doing us a favor. They tend to select litter boxes because it’s the next best thing to sand or soil back in their not too ancient past.

It’s our job to make sure that the litter boxes are consistent with their preferences; in other words, your cat’s preference for box location, hygiene, filler type, and box type is what’s most important because they’re the ones that have to use it. Individual cats have individual preferences, but if they could they would tell us they’d like clean, uncovered boxes placed in quiet corners and filled with soft sand clumping litter.

Litter Box Selection

      These days, the selection of litter boxes and litter filler is nearly endless.  Since the invention of cat litter and a simple box to contain it, there is something to satisfy every budget, every cat, and every location in your home.  Litter boxes, or litter pans as they are sometimes called, are most commonly rectangular and made of plastic.  They can also be square and triangular.  Boxes are generally scooped manually with commercially available litter scoops, but automated boxes are also marketed as ‘self-cleaning’, and still others can be sifted by virtue of perforated insets in the box.  There is even a box that is rolled over to sift itself, sort of.  Although the new generation of boxes that offer new and improved mechanisms to save the cat owner time and energy, most of them still need to be manually maintained to a degree.  And some of them could even startle the cat who is supposed to be the one to use it.  After all is said and done, the best box is always the box your cat will use and use reliably.

      Litter boxes come not only in a variety of shapes, but sizes, too.  Small, medium, and jumbo are frequently offered in any given shape.  It is always better to provide a box that is too large rather than too snug for a cat.  Chubby cats need to feel comfortable entering and turning around in the box, particularly if the box is covered and they have a tight squeeze to fit through the opening.  For obese cats or for multicat households, a plastic storage container intended for under the bed use might be an attractive alternative.  It provides an almost sandbox-like latrine that is sure to please most cats. 

Consider also the depth of the pan. The walls should be high enough to keep sand in but low enough to allow easy access. For very young, aging or ailing kitties, you can replace a standard box with another suitable container.  For example, a 9”x 9” aluminum foil baking pan makes a neat, temporary pan for little kittens.  Aluminum pans come in all shapes and sizes; there should be one for your special needs cat.  Covered litter boxes reduce the escape of odors but they also confine odors and can put off some fastidious cats. They remain a popular choice for many homes but require careful maintenance to avoid insulting a cat’s sense of hygiene.

Remember that your cat’s sense of smell is at least one hundred times more sensitive.  Covered boxes usually have a front entry, however, hooded covers require the cat to hop into the litter box by maneuvering under a hood.  Some cats tend to spray the inside of their litter boxes. Others balance on the side of open boxes or are unsteady due to illness or age.  These cats may do best with covered boxes or boxes with high walls. The top of a front entry covered box can be placed upside down and used as a litter box for these cats.  The walls are high but the opening is easily accessible for physically impaired kitties.  Ultimately, the best cat box is the one your cat will happily and easily use.

Litter Filler Selection

Litter filler comes in clumping sand; regular clay; recycled newspaper; corn, grain or wood based; crystals that absorb odor, and more. There is even a lightweight clumping sand that is appreciated by those of us who are tired of lugging heavy litter buckets or jugs. Given a choice most cats will prefer a soft sand or clay with no fragrance, but you might get lucky and both agree on your preference.

      Given the choice, cats would naturally prefer to eliminate in sand or soil.  They consent to use litter filler because it is a soft, loose substrate that is the next best thing. A wide variety of litter fillers are available. These are marketed to attract the cat owner, but the most important selection criterion is the litter your cat will use.  Some cats are surprisingly choosy and refuse to use the box if their favorite litter is replaced with another.

Stay with basic and simple products. Perfumed filler that promises to deodorize the latrine may repel your cat. The majority of cats seem to prefer the clumping, sand-like fillers. Your cat might be happy to use recycled, shredded newspaper. If you are not sure which your cat will use, offer two or three litter boxes side by side and filled with a different substrate to see which material the cat prefers.

      If you decide to switch to a new brand because of price or availability, mix the old with the new fillers for a week or two to help your cat adjust.  Ultimately, avoid making changes if your cat is reliably using the litter box. The old adage “if it ain’t broke, don’t fix it” seriously applies to cats and their litter box preferences.

Litter Box Maintenance

      Cleanliness is the most important consideration to encourage ongoing litter box use. Cats are very clean animals. Dusty, stinky, and soggy places will be avoided. Consider only what your cat finds acceptable; your cat’s individual tolerance for minimal litter hygiene is the single most important factor.  Litter boxes should be scooped daily.  Fecal material should be removed, and urine balls in clumping litter is easily discarded.  You should also periodically replace all the litter filler. 

Some cat owners tend to scoop out waste and replenish the box with new filler by adding to the older layer.  Molecules of odor accumulate in used sand, even when it is does not adhere to a clump.  Better safe than sorry!  On the other hand, it is not necessary to sterilize the cat’s litter box with detergents and bleach on a monthly basis.  Many cats are repelled by harsh chemical scents, and furthermore, they enjoy the comfort of their own familiar odors in the box.  Rinse with dish soap and hot water once or twice a year unless your kitty has tummy trouble or other medical concerns.

As a rule of thumb, keep at least one box for every cat you live with. Cats share their litter boxes; it is unlikely they will each pick just one to use. You will probably find that some boxes are more popular than others. This could indicate a preference for placement, box type, litter filler, or hygiene of particular boxes, and is important feedback about their preferences.

Kittens and the Litter Box

Tiny kittens must be intimidated by the walls of an adult sized litter box. You could place something that can act as a step up into the big box or you could really think outside the box! Maybe your kitten’s first litter box is a big plastic container with low sides, an old casserole dish or an aluminum foil roasting pan. Gently place the kitten in the clean litter tray soon after each meal and nap, and dig into the top layer of the sand to give her the idea. Kittens usually learn litter box use very quickly. The best teacher is the mama cat. Some orphaned or feral kittens or kittens raised alone are slower to catch on, so be patient. Don’t hover or disturb your cat while she’s using the box. Praise her softly for using the box from a few feet away.

  Training young kittens to use the box is easier if they have watched their mother or another adult cat use it.  However, most young kittens instinctively recognize that the loose, clean litter filler you have thoughtfully provided is an appropriate place to lay their waste.  Simply place your kitten in the box and dig in the clean litter with your own fingers.  That’s usually all they need to get the idea. For young kittens, it is probably most important to make sure that they are able to scale the walls of the box you have selected.  If they are very young, you may need to provide a temporary alternative, as you will soon learn.

House Soiling

Litter box failure must not be viewed as acts of malice or revenge; these are human tendencies, cats are above that. Elimination is a normal form of territorial marking in cats and in most animals. Cats can mark with urine or stool. Territorial conflict with another housemate, the introduction of a new pet, moving to a new home, and a variety of social factors can trigger marking behaviors in susceptible cats.

Territorial conflict between housemates can occur at the litter box location. The bully cat may wait there in ambush; this inhibits the victim cat’s return to this litter location. As tension rises, so does house soiling risk. An important rule of thumb is to provide a minimum of one litter box plus one for every cat in your home. This means that even a single pet cat should have a choice of two litter boxes.

When cats regress in litter box use because of health or behavioral issues, you need to revisit the basics that attracted them to the box to begin with.Place at least one box on every floor for easy access by an aging or sick cat, and an alternative for a cat who is being harassed by others near another litter location. Position boxes in quiet corners of your home and observe which boxes attract the most use. Cats can never have too many litter boxes, but they can have too few. Some cats simply prefer to urinate in one location and defecate in an entirely different location. If there is only one box, or two boxes in one location, the cat who prefers to use an alternate spot has a problem, and so do you.

Causes of Elimination Outside the Litter Box

The first thing to do if your cat fails to use the litter box is to make sure there is no obvious reason it chose not to. For instance, did the door close and block access to the only box in the house? Was your new puppy blocking passage to the box? As many as 13% of pet cats will urinate out of their boxes at some point in their lives. Cats fail to urinate in the litter box for a variety of reasons. Litter box hygiene can deter even the most devoted cat. Each cat has an individual level of tolerance to the accumulation of waste in any given litter box. One cat might continue to use a dirty box that is only cleaned once a week, while a housemate might refuse to enter a box that has been used just once.

If there is no obvious reason for litter box failure, your next decision should be to bring your pet to the veterinarian right away. Urinary tract infections, bladder crystals or blockages are often associated with failure to use the box, and so are constipation or diarrhea from many causes. Cats who are ill or have arthritis, for example, may not make it to the box at the other end of the house or 2 flights of stairs away. Any illness can be associated with a lapse in litter training. It is essential to consult your veterinarian the moment that inappropriate elimination is noted so that medical problems can be detected and treated.

Cats mark with urine from both a crouching or standing posture. Cats who mark with urine may use either or both positions. Urine deposited from a standing position is called spraying. Urine spraying is seen in both males and females, and in both neutered or sexually intact cats of either gender, but is more typical of male cats. Urine marking is a big part of sexual advertising in cats, but sexual hormones are not the only factors that instigate urine marking. Social stress, for instance, puts cats at risk to skip the litter box. Although neutering has an immediate and permanent effect on sex hormones in circulation, inappropriate urination can continue or even emerge long after neutering. Neutering may reduce urine marking, but help from a veterinary behaviorist may be required to resolve it completely. The longer inappropriate urination persists, the more challenging it may be to resolve so get help quickly.

Separation anxiety syndrome exists in cats, and the most common signs include inappropriate urination and defecation. Remember, your cat is not punishing you for leaving him behind when you go on vacation. He just misses you and is trying to cope by marking the territory he loves to share with you.

Defecation outside the litter box can be intentional, but it can also be unintentional. Long-haired cats, such as domestic longhaired cats and Persians, have long, soft hair on their tails, the back of their legs, and even their feet. Fecal balls can adhere to the hair and finally drop off at a distance from the box. Pet groomers or veterinary technicians can trim the long hair. Periodic grooming is a simple step to prevent accidental tracking of fecal balls outside the litter box.

Location, Location, Location

      Cats generally prefer litter boxes in quiet, low-traffic corners. Litter boxes should never be placed close to the cat’s food or water bowls. Feed your cat in another room entirely.  If this is unavoidable, place the dishes diagonally across the room from the box to make the latrine area distinct from the feeding area, or place a barrier of some kind to create a visual obstruction. 

      Access to the litter box must never be blocked.  For example, the door to the bathroom, where many folks place the cat’s box, might be closed when your cat really needs to use his or her own litter box. For this reason, it is recommended to place a minimum of 2 boxes at different locations even if you have just one cat. This way, your cat will always have access to one of the boxes. Providing multiple boxes also helps to distribute their use, in case you fall behind in scooping them!

A Final Word

If it ain’t broke, don’t fix it. If your cats use the box and everyone is happy, don’t change a thing. Avoid the temptation of trying a different litter filler. Replace an old box with a similar one, or introduce a new one before discarding the old one to make sure your cats will accept it. Change is stressful, and stressed cats might reject the change you impose in their world.

Dr. Stefanie Schwartz is a board certified veterinary behaviorist and founder of If you need help with a misbehaving pet, please visit

© Stefanie Schwartz, 2020