Litter Box Problems in Cats

Litter box problems are one of the biggest sources of frustration among cat owners and a leading reason why cats are surrendered to animal shelters, in fact, behaviour problems kill more cats per year than viral infections.

Firstly, cat owners must be aware of the difference between spraying and urinating. Spraying is targeted at diagonal surfaces such as walls and doors, urinating is on a horizontal surface such as the floor or a bed.

Litter box problems can include sometimes using the litter tray and sometimes not, only using the tray for defecation OR urination, but not both.

People often pin litter box issues as the cat being dirty, but it is far from the truth. Cats are exceptionally clean animals, which can make the issue confusing. Why would such a fastidiously clean animal urinate or defecate outside his or her toilet?

What causes litter box problems?

Causes can be divided into behavioural or physical and it is important to get to the bottom of the underlying cause to implement an effective treatment to resolve the issue.


Behavioural litter problems occur when there is no underlying medical condition and can stem from dirty litter trays, litter trays placed in the wrong location, inter-cat issues, incorrect litter tray size, dislike of the type of litter in the tray and highly scented litters. All of these common litter tray problems can lead to the cat finding a preferable alternative.

Dirty litter trays

Cats are fastidiously clean and do not like dirty litter trays. Trays can quickly become dirty because there aren’t enough (one tray per cat plus one for the house), or they are not maintained as often as they should be.

Scoop out solids once a day and once a week, remove and replace all the cat litter with fresh. It can also help to rinse out the tray with hot soapy water to remove odours.

Litter trays in the wrong location

The location of the litter tray(s) is important. Avoid high-traffic areas and do not place trays near the cat’s food and water bowls. Cats may also avoid litter trays that are close to a noisy appliances.

If there is more than one cat in the home, place litter trays in different locations, and have at least one per level.

Cats like privacy, but they don’t want to feel hemmed in when they are using the litter tray, so if space permits, look for an area where the cat has more than one escape route.

Always place litter trays away from food and water bowls as cats don’t like to eat where they go to the toilet.


Cats can develop an aversion to the litter tray if they are ambushed by another cat, dog or child, which can lead the bullied cat to seek out ‘safe’ alternatives if they feel they are vulnerable to the alpha cat while in the litter tray.

Incorrect litter box size

As a rule, the tray should be 1.5 times longer than the cat (excluding the tail) and large enough for the cat to comfortably turn around. If you have a larger cat, a large storage container can be used instead of a litter tray.

The opposite goes for kittens, they should be provided with a smaller tray with low sides to that they can easily climb into the tray.

Types of litter trays

There is so much variety, plain litter trays, covered litter trays, self-cleaning trays, large storage boxes. Sometimes it can take a bit of trial and error to find the right tray for your cat(s).

Covered litter trays give the cat some privacy, but it can also hold in the smell more than an open tray (which is great for us, but not so much for the cat), and some cats can feel trapped in such a small and enclosed space, especially if the cat has been ambushed previously.

Open litter trays may put some cats off due to the lack of privacy. Large storage boxes are great as they reduce tracking, but can be difficult for kittens or senior cats to climb into.

Substrate aversion

Some cats can be fussy about the type of litter they will use. I always recommend talking to the breeder or shelter about the litter the cat is used to when picking up a new cat and staying with that brand at least initially. If you do choose to change the type of litter, do so over a few days by gradually adding the new while reducing the amount of the old litter.

Highly scented cat litter

We may like cat litter which is scented but most cats don’t like having strong smells so close to their nose.


Medical causes include blockage, cystitis, bladder, constipation, diarrhea, declawing pain and arthritis.

Urinary blockage

A full or partial blockage can happen in the urethra which prevents urine from passing out of the body. This is extremely uncomfortable to the cat and if a full blockage occurs, is life-threatening. Urinary blockages occur mostly in male cats who have a narrower urethra than the female.

If a partial blockage occurs, the cat may attempt to urinate anywhere he can relive himself which can develop into a habit due to associating pain or discomfort in the litter tray.

Urinary tract infection

A urinary tract infection (UTI) occurs when the usually sterile urinary tract is colonised by bacteria (or less frequently viruses). It can develop anywhere along the urinary tract including the kidneys, ureters, bladder and urethra and can occur due to bacteria descending from the perineum into the urinary tract. Cats who hold onto urine for too long, cats who have been recently catheterised or diabetic cats are at increased risk.


Cystitis is an infection or inflammation of the bladder and occurs more often in female cats. She will have a constant feeling of needing to urinate, even if her bladder is not completely full.

Bladder stones

These rock-like form when minerals build up on the bladder and form into small stones. Stones can cause partial or full obstructions as well as irritation to the bladder wall.


Constipation is a reduction in the frequency of bowel motions along with difficulty passing stools as they become hard and dry. There are several causes, which include dehydration, reluctance to defecate due to dirty litter trays or pain, blockages, certain drugs, neurological disorders, systemic disease and a narrow pelvis.

A constipated cat may experience pain when attempting to defecate which can lead to litter tray aversion as they associate the litter tray with pain. Once this develops, they will seek out other places to defecate.


Diarrhea is the passage of loose and watery stools with several medical causes including medication, food indiscretions, medication and systemic diseases. In some cases, diarrhea can come on so fast that the cat doesn’t have the chance to get to the litter tray in time.


Osteoarthritis is a painful condition in which the shock-absorbing cartilage which cushions the joints wears down and is eventually lost. This type of arthritis is most common in middle-aged to older cats, obese cats, and cats who have suffered previous trauma.


Declawed cats can experience pain when digging in litter trays after surgery which once again, leads to litter tray aversion due to its association with pain. The cat may seek out softer places to go to the toilet such as on beds or furniture.

Identifying the cat in multi-cat households

It is not always possible to witness which cat is urinating or defecating outside the litter tray. The veterinarian can prescribe fluorescein dye pills or administer fluorescein via subcutaneous injection. The cat will pass bright yellow-green fluorescent urine for 24 hours after administration when viewed with a black light.

Add a teaspoon of finely grated non-toxic crayon in different colours to cat food which will harmlessly pass out of the body via the feces. Obviously, it will be necessary to feed each cat separately and each cat has his or her own colour.


Any changes in litter box habits need to be evaluated by a veterinarian to determine if there is a medical or behavioural cause. Toileting issues need to be nipped in the bud quickly before the cat develops a preference for the new area and to address underlying health issues which may have triggered it.

The veterinarian will perform a complete physical examination and obtain a detailed medical history from you which will include:

  • How long ago did the cat start urinating and defecating outside the tray?
  • Does the cat use the tray at all?
  • Have you noticed any other symptoms such as blood in the urine, crying, frequent genital licking?
  • Does the cat show a location preference?
  • Does the cat cry in the litter tray?
  • How many litter trays do you have?
  • What kind of litter do you use?
  • How often do you clean the litter trays?
  • How does the cat behave around the litter box? Signs a cat may not be happy with the tray include sniffing it and walking away, balancing on the lip of the tray, putting two feet in the tray and not burying the urine or feces, scratching outside the litter tray, both urination and defecation are occurring outside the box.

Diagnostic workup:

Diagnostic tests will be necessary to rule in or out an underlying medical cause, this may include:

  • Baseline tests: Biochemical profile, complete blood count and urinalysis to evaluate the overall health of the cat and look for bacteria or crystals in the cat’s urine.
  • Culture and sensitivity: If bacteria is found in the urine, a culture and sensitivity will be performed to determine the type of bacteria present and which antibiotic is most effective to treat the infection.
  • Imaging studies: Xrays or ultrasound to evaluate the bladder for signs of inflammation or stones, urinary blockages and tumours.


Treatment will depend on the underlying cause. Addressing medical issues should hopefully see the cat returning to the litter tray all the time. Sometimes, even if there was a medical cause, it will take a little while to encourage the cat to use the tray as they may still associate it with pain.


  • Antibiotics for bacterial infections.
  • Stone dissolving diets for struvite stones.
  • Surgery to remove calcium oxalate or bladder stones.
  • Switching to a softer litter for declawed cats.
  • Stool softeners and fluid therapy to treat constipation as well as address the underlying cause (if one is found).
  • Cats who are prone to constipation may also be switched to a canned diet to increase water consumption.


Behavioural causes will require a complete history to determine a possible cause. Once this can be established, then therapies will be aimed at resolving issues. Litter trays must be made as appealing as possible to encourage the cat to use them instead of finding alternate places.

  • Litter tray maintenance is a crucial step in eliminating litter box problems. The trays must be kept clean at all times. Scoop twice a day, empty and wash once a week, mop floors and wipe down walls where litter trays are located. When re-filling, add a 1-2 inch layer of litter only.
  • Avoid litter tray liners, they may be convenient, but most cats don’t like them.
  • Make sure there are enough litter trays in the house and don’t line them up side by side but place them in different locations.
  • If substrate avoidance is suspected, pet owners are encouraged to try a variety of different types of cat litter (one type per tray), to see if a preference can be determined.
  • Look at where the cat is going to the toilet, including the surface and switch litter types to reflect that. Some cats prefer soft litter, in which case, look for a finer type.
  • Have a variety of litter trays in the home, which include covered and uncovered.
  • Switch to a scent-free cat litter.
  • Cats with arthritis and young kittens will benefit from litter trays that are easy to climb into and out of.
  • If possible, block access to where the cat has been going, or add a litter tray to the location. Always place food and water bowls away from litter trays.
  • Inter-cat aggression can take time and effort to resolve. The home should have separate resources for each cat, which includes litter trays, food and water bowls, beds and cat trees.
  • Synthetic pheromones (Feliway) can also help to restore a sense of communal wellbeing by mimicking the cat’s own feel-good pheromones Feliway increases emotional stability. Feliway is available as a plug-in and spray. Once the area is clean, spray Feliway directly over the soiled area and re-apply daily. The plug-in diffuser can also be used to provide a constant release of pheromone into the home.
  • Pharmacological intervention with anti-anxiety medications may be prescribed in some cases. Medical therapy may be necessary for cats stressed or anxious and may include benzodiazepines (diazepam, clorazepate), tricyclic antidepressants (amitriptyline, nortriptyline, clomipramine), non-specific anxiolytics (buspirone) and selective serotonin reuptake inhibitors. Medical therapy must be used in conjunction with environmental changes and behavioural modification. Baseline tests are essential before commencing medical therapy due to the risk of hepatoxicity. Most cats will need to remain on medications for life, however, the dose can be tapered after 2-4 months. Cats placed on medication must be monitored closely by a veterinarian.

Cleaning cat urine and feces

Cleaning cat urine

Cat urine has a pungent odour, particularly if it hasn’t been cleaned immediately. Adult cat urine contains felinine, a sulphur-containing amino acid. Felinine is odourless until bacteria begins to break it down.

There are several commercial products to remove cat urine that use enzymes to break it down. White vinegar and bicarbonate of soda are cheap and effective alternatives.

Do not use ammonia or ammonia-based products, as cat urine contains ammonia the use of ammonia to clean cat urine will attract the cat back to the spot.

Always wear washing up gloves when cleaning cat urine or feces.

  • If the urine is fresh, blot as much as you can with a paper towel.
  • Apply the cat urine remover and leave as per instructions. If using vinegar and bicarb, spray vinegar onto the stain, it should be wet but not saturated. Follow by sprinkling bicarbonate of soda over the damp area. Leave for 10 – 15 minutes and remove with a damp sponge. It may be necessary to repeat this step several times to completely remove the odour.
  • Cat feces can be removed with a paper towel and discarded in the toilet. If the feces is on the carpet, once removed, use kitchen spray, warm water and a sponge or cloth to remove any residue. If it is on tile or wood, spray white vinegar or kitchen spray over the area to remove any residue.
  • Blot as much urine or remove feces with a paper town on bedding, and if possible, wash in a washing machine. Feather bedding will need to be dry cleaned. I recommend (from experience), replacing feather bedding with washable while dealing with litter box problems to avoid the expense of repeat dry cleaning.
  • If the cat has urinated or defecated on a mattress, blot away as much urine as possible and remove feces. Spray with a urine remover or the vinegar and bicarbonate of soda mix. A mattress protector is recommended, the cheap plastic ones are best.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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