Feline House-Soiling

Cartoon of cat urinating outside the litterbox

Urinating outside the litterbox or feline house-soiling is the most common reason why cat owners abandon, relinquish, or euthanize their feline companions.  Since it is nearly impossible to find a new home for a cat with a history of peeing outside the litterbox, most cats relinquished to shelters for litter box problems will be euthanized.  Your feline healthcare professional can help you and your cat have the best chance of successfully resolving this very difficult problem.

Peeing outside the litterbox is always a challenging problem.  Addressing it successfully nearly always requires identifying and treating physical problems, and may involve working to ameliorate emotional stress as well.

Four Basic Causes of Feline House-Soiling

1.  Abnormal Urine Chemistry from Species-Inappropriate Nutrition

Urinating Outside the Litterbox – Unnatural, irritating urine chemistry resulting from biologically inappropriate diet is perhaps the single most common cause of urinating outside the litterbox. Unfortunately, the vast majority of commercially manufactured cat foods are NOT biologically appropriate.

Cat urine is naturally acidic, but foods containing plant ingredients and carbohydrates create alkaline urine.  Cat urine is naturally mid-range in concentration, but dry foods create very concentrated urine. In combination, this is the perfect storm to create chronic lower urinary tract irritation and inflammation in the cat, the symptoms of which are indistinguishable from bladder infection.  A cat who feels pain often enough in the litterbox will learn to associate that pain with the box, and may thereafter avoid using it.

2.  Medical Problems

Medical problems, in general, are a far more common cause of urinating outside the litterbox “behavioral” issues.  Absolutely any health problem that creates discomfort can cause a kitty to miss or avoid a litter box. Medical problems that commonly lead to house-soiling include:

  • Arthritis
  • Inflammatory Bowel Disease
  • Periodontal disease (diseased, painful teeth and/or gums)
  • Bladder stones
  • Urinary tract infection (extremely rare in young and middle-aged cats)
  • And any other disease or disorder!

The first step in addressing urinating outside the litterbox problems is to see your feline veterinarian.

3.  Litter Box Problems

Not Enough Litter Boxes: 

The general rule of thumb for an adequate number of boxes is the number of cats PLUS ONE.  For multiple-floor dwellings, a litter box on each floor is helpful, especially for older or arthritic cats.  (Two or more litter boxes right next to each other count as only one box.)

Litter Box Locations Cats Don’t Like: 

Many litter box locations will make a cat avoid the box.  Locations to avoid include laundry rooms, “box canyon” rooms (rooms with no easy escape), high traffic areas, spots near cat doors or flaps, and spots near children’s rooms.  

In cases of inter-cat aggression, litter boxes should be placed in different rooms, so that box access cannot be easily blocked.

Food and water should be not be placed in proximity to a litter box.

Litter Box Characteristics Cats Don’t Like:

  • No Covered Litter Boxes:  elimination is a vulnerable moment for any cat in the wild.  Cats need to feel safe in the box, which means good lines of sight and more than one escape route.  Covered boxes make many cats feel unsafe. They also trap odors, which is another big offender for cats!  (This is applicable to furniture built to contain litter boxes as well.)
  • Size Matters:  most commercially manufactured litter boxes are too small for all but the tiniest cats.  Most kitties will tolerate a small box, but many won’t. This is especially true for cats with arthritis in the lower back and tail — a cat should be able to turn around in the litter box without putting pressure on his tail, and if he can’t, he may choose a more comfortable place to eliminate.  (We often recommend under-bed storage boxes, available inexpensively at stores like Target, since they are a great size for most cats, and can be cut easily to make a lower door. Litter boxes should be at least 1.5 times the length of the cat from the nose to the base of the tail. Suitable alternatives can include concrete mixing trays or storage containers. You can place the lid behind the box to protect the wall, or cut a door in a taller storage box.)
  • Height Matters Too:  Young, healthy cats don’t care how tall the walls of a litter box are, but older cats, especially those with shoulder arthritis, may experience pain trying to get into a box with walls that are too high.  
  • No Litter Box Liners:  the sound made by the rustling of plastic litter box liners is a big turn-off for many cats, who will often use a box without a liner just fine.
  • No Electronic Litter Boxes:  Sound and motion both are big players in creating feline aversion to electronic self-cleaning litter boxes.  The tech may seem cool to us people, but it is frightening and aversive to many cats.

Kitty Litter Your Cat Might Dislike: 

Different types of litter can be good or bad for different cats.  Nearly all cats dislike scented litter. Many dislike dusty litter.  Some will dislike fine-grained litter or chunky litter. Most cats prefer soft, unscented clumping litters.  Experimentation can help find a litter your cat prefers. For preference evaluation, provide multiple boxes with different litters and variable litter depths.

Soiled Litter Boxes: 

Cats by nature are very clean.  Many will refuse to use a box that already contains any urine or feces.  Cleaning out the box twice a day is a must for nearly all cats, and more often may be better for the more fastidious kitty.  Wash the litter box every 1-4 weeks using soap and hot water only. Avoid strong chemicals or any ammonia-based products.

4.  Marking Behavior

  • Urine spraying is a normal part of feline behavior in the wild, in which cats mark their territory with scent. Marking behaviors can include both urine spraying and depositing feces (also called middening).
  • Unneutered male cats and most unspayed females will mark as part of their normal sexual behavior. Spaying and neutering can dramatically reduce this behavior.
  • Anxiety-related marking occurs in some cats, in response to a change in the environment, especially the core areas where the cat eats, sleeps, and plays.
  • Outdoor cats can trigger marking behaviors, through smell (if one is urinating on or near your home) or sight (if your cat can see them through a window) or even sound.
  • Cats often target items with new or unrecognized smells such as backpacks and shoes, and will also often target items that are “out of place,” such as laundry left on the floor.
  • Urine already present and “soaked in” to carpets and drywall can trigger further marking behaviors.

Treatment and Management of Feline House-Soiling

Identify and Treat Medical Problems:  

The first step in addressing urinating outside the litterbox problems is to see your feline veterinarian.  She will help identify and treat any medical problems that may be causing or influencing litter box avoidance.  

Feed a Species-Appropriate Diet:  

Make sure your cat is eating a truly carnivore-appropriate diet.  (This does not include ANY of the so-called “prescription diets.”)  See our posts on Feline Nutrition to learn more about what a carnivore-appropriate diet is.

Evaluate Your Litter Boxes:  

The design, placement, and management of litter boxes are critical for encouraging acceptable toileting habits. When peeing outside the litterbox occurs, always evaluate your litter boxes. Review the section on Litter Box Problems above, and make changes as needed.

Remove Marking Triggers:

  • Neuter or spay your cat to eliminate hormonally induced marking behavior.
  • Identify and address potential sources of emotional stress for your cat to the extent possible.
  • Restrict the perceived threat of other cats:  
    • If your cat never goes outside, you can use motion activated water sprinklers to make your yard unattractive to feline visitors.
    • Laying plastic carpet protectors upside down in front of sliding glass doors creates an uncomfortable surface and may dissuade other cats from sitting close to the house.
    • Covering the lower parts of sliding glass doors (and relevant windows) with something opaque can help remove the visual triggers.
    • If the outdoor cats are known to you, speak with their owners about the problem.
    • In the case of strays, contact Animal Control or a rescue organization to trap and remove the stray cats from your area.
  • Remove or block pet doors that might allow strange cats to enter your home. Use microchip or magnet operated pet doors to prevent access to cats other than yours.
  • If your cat targets dirty laundry, shoes, suitcases or the like, be sure that no one in the home makes those targets available.
  • Cleaning urine-marked areas thoroughly will reduce a cat’s habit of refreshing its scent on the marking site.
    • Use a black light (UV) to find soiled areas.
    • Clean affected areas with a good quality urine odor and stain remover according to the type of surface the cat has soiled. Test products on an inconspicuous area first and clean a sufficiently large area to remove the odor, which may be up to three times the size of the soiled area.
    • Avoid using ammonia-based cleaners, which smell like urine to a cat.
    • Check cleaned areas often in case they’ve been re-soiled.
  • Depending on the amount of damage already done, it may be necessary to remove and replace carpeting, drywall, and even wooden subflooring to completely remove urine smell.  If the subfloor is concrete, it should be painted with an effective sealer prior to replacing the carpet. If the soiled flooring is tile, the grout may need to be sealed or even replaced.  Any fluid-permeable flooring may need to be removed and replaced.

Additional Considerations for Urinating Outside the Litterbox

cartoon of cat spraying the spot where they urinating outside the litterbox
  • Ensure that all of your cat’s environmental needs are being met. For more information visit www.catvets.com/cat-owners/brochures or www.icatcare.org/vets/guidelines.
  • Never punish your cat for peeing outside the litterbox. Punishment can lead to fear-related aggression, reduces the bond between cat and human, and encourages urine marking in less obvious areas.
  • Likewise, the use of aversive odor products, such as citrus sprays, is almost never helpful — it simply prompts the cat to mark elsewhere.  
  • Consider use of comforting synthetic pheromones. Spray Feliway on affected areas after cleaning to reduce the likelihood of re-marking. After individualizing toileting areas for the cat’s preferences, adding a Feliway diffuser in the room most frequented by the cat reinforces the cat’s feeling of security.

In Closing

Feline house-soiling can be a frustrating problem. A resolution requires patience, as it can take some time to determine what is causing these behaviors, and may involve making changes to several aspects of a cat’s home environment and care.

If your cat is urinating outside the litterbox, please contact your feline veterinary practice immediately. The sooner these issues are addressed, the happier everyone will be, including your cat. Working with your feline veterinarian to identify the causative factors for peeing outside the litterbox, and effectively addressing those factors, will dramatically increase the chance of resolving the house-soiling issue.

By understanding and providing for your cat’s environmental and medical needs you can help you and your cat live a long and happy life.

AAFP and ISFM – Strategic partners in feline health and welfare. Together, improving cats’ lives worldwide.