Cat litter box problems: why a clean cat starts going elsewhere

Quick answer

A cat that has always used its tray and suddenly stops is not being spiteful, dirty, or untrained. Cats do not toilet indoors to make a point. Something has changed: their body, their tray, or how safe they feel getting to it.

Work through it in that order. Medical first, because urinating outside the tray is the single most common presenting sign of urinary disease in cats. Then decide whether you are looking at spraying or at toileting, because they are different problems with different solutions. Only then audit the tray itself.

• A male cat straining in the tray and producing little or nothing is a life-threatening emergency, not a behaviour problem.
• Spraying is done standing, against a vertical surface. Toileting is done squatting, on a horizontal one.
• Most homes have too few trays, and they are too small, in the wrong places, with the wrong litter.
• Never punish. Punishment increases anxiety, and anxiety is the main driver of both marking and idiopathic cystitis.
• Clean with an enzymatic pet cleaner. Ammonia-based products smell like urine to a cat and invite a return visit.

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A cat straining to urinate and producing nothing is a medical emergency.

This is most common in male cats, whose urethra is long and narrow, and it means the bladder cannot empty. Owners frequently mistake it for constipation, or for the cat being fussy about the tray. Signs are repeated trips to the tray, straining, crying out, licking at the genitals, vomiting, and a cat that becomes flat and unwell. An obstructed bladder causes kidney failure and dangerous potassium changes within a day or so and it is fatal without treatment. Go to a vet immediately, out of hours if necessary.
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Decide in 60 seconds

Rule one: medical before behavioural

Urethral obstruction.

Covered above and worth repeating because owners lose cats to it every week while trying litter changes. Straining with little or no output is an emergency.

Feline idiopathic cystitis.

The most common cause of lower urinary tract signs in cats under about ten, and there is no infection to find. It is a painful bladder condition strongly associated with stress: multi-cat conflict, indoor confinement without enrichment, low water intake, a change in the household, or a cat that can see other cats through the window.

The cat associates the pain with the tray, which is where it happened, and starts using somewhere else. That is why a cystitis case often continues to toilet in odd places after the pain has resolved.

Urinary tract infection and bladder stones.

Infection is more common in older cats and in cats with kidney disease or diabetes. Stones and crystals cause pain, blood and sometimes obstruction.

Kidney disease, hyperthyroidism and diabetes.

All three increase urine volume. The tray fills faster, the cat needs to go more often, and a tray that was adequate is now unpleasant or full. A cat producing much more urine than it used to, and drinking more, needs a blood and urine test rather than a new litter.

Arthritis and pain.

Under-recognised and very common in older cats. A cat with sore hips, elbows or spine finds it hard to climb into a high-sided tray, to squeeze through the flap of a covered one, to crouch comfortably, or to get up and down stairs to reach the tray at all.

The tells are subtle: hesitating at the tray edge, perching with the front feet in and the back feet out, urinating over the side, or choosing a soft flat surface such as a bath mat or a duvet, which is far easier on painful joints than a rigid tray with a lip.

Constipation, diarrhoea and anal gland problems.

A cat with painful defecation associates the tray with the pain. A cat with diarrhoea may simply not reach the tray in time.

Cognitive dysfunction.

In older cats, disorientation, changed sleep patterns and forgetting where the tray is.

Ask for a urine sample to be tested, not just a physical examination. Non-absorbent litter for collecting a sample is available from most practices, and a sample the cat produced at home is far more informative than a stressed cat in a consulting room.

Rule two: spraying or toileting

These look similar to an owner and are completely different behaviours.

Spraying.

The cat stands, backs up to a vertical surface, raises the tail, quivers it, treads with the back feet, and releases a small volume at height. Common targets are doors, windows, curtains, the sides of furniture, new items brought into the house, bags, and anything smelling of outdoors or of a visitor.

Spraying is communication, not elimination. It is done by neutered cats of both sexes as well as entire ones, and it is driven by social insecurity: another cat in the home, a cat coming through the flap, a cat visible through a window, or a change that has made the territory feel unstable.

The cat almost always still uses its tray for actual urination and defecation.

Toileting outside the tray.

The cat squats normally on a horizontal surface and passes a full bladder or a normal stool. The location is usually soft and absorbent: a rug, a bed, a pile of laundry, a bath mat, a sofa.

This means either the tray is unacceptable, the route to it is unacceptable, or something hurts.

Middening.

Faeces deposited in an obvious, exposed place rather than buried. Uncommon, and usually a marking behaviour in a household with significant tension.

Write down, for a week, what was passed, where, on what surface, and in what posture if you saw it. That record answers most of this question on its own.

Rule three: audit the tray

A common and unwitting mistake: the tray, the bowls, the bed and the scratching post crammed into one corner. Cats do not eat next to their toilet, and a covered tray in a corner has only one way out.

Number.

One tray per cat plus one spare. In a two-cat household that means three trays.

Location, not lined up.

A row of three trays in the same corner is one location as far as a cat is concerned, because a single cat can sit in the doorway and control all three. Put them in genuinely separate parts of the home, on each floor the cat uses.

Size.

Most commercial trays are too small. A tray should be roughly one and a half times the length of the cat from nose to base of tail, so the cat can turn around, dig and choose a spot. A large plastic storage box with a low-cut entry is a cheap and excellent tray.

Open, not covered.

Most cats prefer an open tray. Covered trays concentrate odour, restrict the view, and have a single exit, which makes them an ambush point in a multi-cat home. If your cat has always liked a covered tray, keep it, but add open ones as well.

Entry height.

Low. An older or arthritic cat needs to step in rather than climb in. Cut down one side of a storage box if necessary.

Litter type.

Most cats prefer a fine, sand-like, unscented clumping litter. Scented litters, crystals, pellets, and anything with a strong deodorising additive are common reasons for refusal. Cats also dislike liners, which catch their claws.

Depth.

Deep enough to dig properly. A thin layer over hard plastic is unsatisfying to a cat and a common cause of the cat scratching the floor beside the tray instead.

Cleaning.

Scoop at least once daily, ideally twice. Wash the tray regularly with hot water and an unscented detergent. Avoid strong disinfectants: pine and phenol-based cleaners are toxic to cats, and heavily perfumed products put cats off the tray.

Placement.

Quiet, away from food and water bowls, not next to a washing machine or boiler that starts unexpectedly, not in a through-route, and with two ways out. A tray in a corridor a dog uses, or in a cupboard with the door sometimes shut, is not a usable tray.

Change one thing at a time.

If you are changing litter, offer the new one in an additional tray alongside the old one rather than switching. Let the cat vote.

The stress side, in multi-cat homes

Cats are not naturally group-living in the way dogs are, and most multi-cat households contain more cats than the space really supports.

Multiply and distribute every resource: food bowls, water bowls, beds, high places, hiding places, scratching posts and trays. Put them in different rooms, so that no single cat can control access to everything by sitting in one doorway.

Deal with the outdoor cats. A neighbourhood cat visible through a patio door, or coming through the flap, is one of the most common and least-noticed causes of spraying and of cystitis. Block the lower part of the glass with removable film, fit a microchip-operated flap, and remove any food left outside.

Increase water intake. More water dilutes the urine and reduces bladder irritation. Use several bowls in different rooms away from food, consider a fountain, and consider wet food if the cat is on dry only.

Add height and hiding places. A cat that can get up and away from another cat is a cat under less pressure.

Keep changes gradual and give the cat a room that stays the same during building work, moves and new arrivals.

Cleaning up properly

Use an enzymatic cleaner formulated for pet urine. Enzymes break down the compounds that carry the smell rather than masking them.

Never use ammonia-based cleaners. Ammonia is a breakdown product of urine, so to a cat you have just relabelled the spot as a toilet.

Do not use bleach on a spot where the cat has urinated, and never mix cleaning products.

Blot rather than rub. Rubbing pushes urine deeper into carpet backing and underlay.

Treat the underlay as well as the carpet if the amount was significant, or the smell will persist and the cat will return.

Find every spot. A ultraviolet torch in a dark room shows urine that the nose alone will miss.

Once a spot is clean, change what it means. Put a food bowl, a bed or a scratching post there, since cats do not usually toilet where they eat and rest.

The toilet-training fad

Training a cat to use a human toilet is popular online and is a bad idea for several concrete reasons.

It removes your ability to monitor output. Litter is how owners notice a cat urinating more, urinating less, straining, or passing blood, and those are the early signs of kidney disease, diabetes, hyperthyroidism and urinary obstruction. Sending it all down the pan removes the single most useful health monitor in the house.

It requires balancing on a rim. Kittens can do it. Older, arthritic, overweight or unwell cats often cannot, and cats do fall in.

It removes digging and covering, which is a strong innate behaviour rather than a habit.

It depends on a door being open and a lid being up, every time, all night.

And when a cat becomes unwell and can no longer manage it, there is no tray to fall back on, so the cat goes on the floor and the owner concludes it is behavioural.

If you have already trained a cat this way and it has started going elsewhere, put a normal tray back in as a first step while the cat is investigated.

What never to do

Do not punish, shout at, or startle the cat. Do not rub its nose in it. Do not use water sprays, alarms, or shaking cans. Every one of them increases anxiety, and anxiety is the mechanism behind both spraying and idiopathic cystitis.

Do not restrict the cat's water in the hope of fewer accidents. It concentrates the urine and makes urinary disease worse.

Do not shut the cat in one room with a tray as a punishment. Confinement is sometimes used therapeutically to re-establish tray use, but it should be a comfortable, resource-rich room and part of a plan, not a sanction.

Do not add another cat for company. It almost always increases pressure in the household.

Do not assume it is behavioural because the cat seems well otherwise. Cats hide illness reliably.

Do not switch litter suddenly, and do not use scented litter to control smell. The answer to smell is scooping more often.

When to get help

Go immediately for a cat straining without producing urine, crying in the tray, repeatedly visiting the tray with nothing to show, licking at the genitals, vomiting or becoming flat. In a male cat, treat this as a same-hour emergency.

Go the same day for blood in the urine, obvious pain on urinating, or a cat that has not urinated at all in a day.

Book an appointment this week for any change in toileting, for increased drinking and urinating, for weight loss, for a cat that has started missing over the side of the tray, and for an older cat that has become hesitant about climbing in.

Bring the diary, photographs of the soiled areas, a note of every tray and its location, the litter type, how often it is scooped, how many cats live there, what changed in the household in the past few months, and a urine sample if you managed to collect one.

Reward the cat for using the tray if you happen to see it, and never react to what happens elsewhere. Only one half of that pair does any good.

The end point is a cat with enough space, enough trays and enough places to retreat to that it never had a reason to look elsewhere.