House Soiling in Cats

If your cat has started to urinate or defecate outside of their litter box, you’re not alone.  This issue is the number one source of behaviour-related complaints from cat owners.  Fortunately, you can solve this problem if your patient and make adjustments to convince the cat to start using their litter box appropriately again.

The first step is a trip to the veterinarian to make sure your cat is healthy and free of medical problems. Things like diabetes or kidney disease may be causing your cat to drink more and, as a result, need to urinate more frequently. Bladder infections may also create a greater sense of urgency to urinate, leading to urinating around the house or in unusual locations. Other issues, such as feline idiopathic cystitis (sometimes called “Pandora syndrome”), or bladder stones may also lead to inappropriate urination.  Arthritis may prevent a cat from using the litter box easily, and constipation issues may result in passing stool outside of the box.

At the time of their physical exam, the veterinarian will also quiz you to confirm that your cat is exhibiting inappropriate urination rather than urine marking.  Marking is a behaviour characterized by spraying urine on vertical surfaces such as walls or drapes; your cat may continue to use the litterbox normally otherwise. While marking is generally seen in unneutered males, it can occur in neutered males and sometimes spayed females. Marking is generally either done to signal territory boundaries, or as a means of reducing anxiety. When it occurs, it generally indicates social anxiety amongst the cats in the house. Treatment is aimed at reducing this tension in the house, and generally involves making sure there are plenty of resources in the house for all the cats (litter boxes, feeding stations, hiding places, water bowls and sleeping / perching areas). Avoiding punishment of “bully cats” and providing positive human-cat interactions through play or training, can also often help.

A good source of information on reducing stress for your cat ( from the American Association of Feline Practitioners ) can be found at .

If a clinical examination and appropriate tests come back as “all clear”, then we can start to address reasons why your cat may have decided to stop using the litter box. The first step is to ensure that everything about your cat’s litter box is to their liking. Factors that need to be considered include:


Cats are very clean animals, and if the litter box is too dirty, they’ll look for somewhere else to go. Make sure you clean the litter box frequently (twice a day is ideal), and that it is thoroughly cleaned out and aired at least once a week.  Adding a second litter box may also be a good idea.

Box type and filler

Many people choose a covered litter box to reduce odour in the house and to keep the urine and feces out of sight. While a covered box may be better for you, it may be stinky and unpleasant inside for your cat. Similarly, scented litters may help to mask odours, but they may put your cat off using the litter box as a result.  The best option is to use a plain box and unscented litters.

Current research suggests that size is one of the most important aspects in encouraging a cat to use the litter box.  Many commercially available boxes are too small and using a plastic storage tote or sweater storage box may be a better option. Most cats also don’t like automatic litter boxes, or litter pan liners.

Cats that fail to cover their urine or feces may be demonstrating an aversion to the type of litter in the box. Many cats prefer clumping litter, so, if you’re not already using this option, switch to this type of litter. It will make cleanup easier as well. However, you may need to experiment by using several litter boxes with different litter options (a so-called “litterbox cafeteria”). Place different type of litter in each box, at varying depths, and check to see which option they choose. If your cat has shown a preference for urinating on the rug or furniture, consider making a rug box (an empty box with a soft washable material such as a throw rug), and see if they’ll use that option.


Keep your cat’s box should away from their food and water dishes and choose a place where they can get to easily. A location where your cat can see what’s coming and feel safe in is also important to reduce stress and increase the box’s attractiveness.  If you have more than one cat in the house, add additional boxes – urine and feces can be used in a war over territory, so more boxes mean cats don’t have to share if they don’t want to. A general rule of thumb is one box per cat, plus one extra.

Cleaning where they’ve soiled

To keep your cat from soiling an area where they’ve previously made a mess, you need to clean the area with an odor-neutralizing product (available from us or from pet stores).  These products will work to destroy the odour enzymatically rather than simply masking them. Following cleaning, cover the area with foil, plastic sheeting, or plastic carpet runners (with the points sticking up) to discourage your cat from returning the area. The odour-neutralizing cleansers take a while to work, so it’s best to figure on blocking off the area for a couple of weeks.

Retraining your cat to use the litter box

If these suggestions don’t clear up the problem, you may need to keep your cat confined to a small area for a few days.  Make sure this room doesn’t have options for them NOT to use the litter box (i.e. no carpeting, no pile of dirty laundry). If you choose to use the bathroom, block off the bathtub or leave an inch of water in the bottom to discourage them from using it as a giant litter box. Once your cat is using the litter box reliably, slowly let them expand their territory again, making sure to keep up with the above-noted suggestions.