Cat weeing outside the litter tray: urinary tract first

Reading time 6 min · Level 1: Why the symptom happens

The short answer: When a house-trained cat starts weeing outside the litter tray, the first question is always whether it is ill. Urinary problems are common and cause exactly this behaviour: the cat wees often, in small amounts and in the wrong places, sometimes with blood. If the cat keeps going to the tray and nothing comes out, it is an emergency, especially in a male cat. Once the vet has ruled out illness, the answer usually lies in the tray, its position or stress. A cat never wees in the wrong place to punish you.

Start with the urinary tract

Agria writes that a cat weeing indoors should be examined by a vet, and that it is not unusual for the behaviour to have a medical cause, or for illness to have developed because of stress, the environment or social problems³. Signs that point to the urinary tract are that the cat¹:

• wees often and a little at a time,
• has blood in its urine,
• cries or makes noises while weeing,
• goes to the tray often without producing anything,
• licks a lot around the genitals or the lower belly.

1. Bladder inflammation with no known cause. Called idiopathic cystitis, it probably accounts for more than half of all cases of lower urinary tract problems in cats. It most often affects young and middle-aged cats, and being overweight, living strictly indoors, eating only dry food and stress are known risk factors⁴. The painful urge means the cat sometimes tries to wee on the floor or on the bed.

2. Urinary tract infection and bladder stones. These can cause leaking, frequent urges and bloody or foul-smelling urine¹.

3. Urinary blockage. A stone or a plug of cells and crystals blocks the urethra, most commonly in male cats, which have a narrower urethra. The cat strains to wee with no result or only a few drops. It is often mistaken for constipation. The more hours pass, the worse the cat becomes, and the condition can lead to acute kidney failure².

4. Increased thirst. A cat that drinks more needs to wee more often and does not always make it to the tray. Kidney disease and diabetes are two common causes of increased thirst¹.

5. Joint pain. An older cat with arthritis may find it painful to step over a high edge and choose the floor next to the tray instead¹.

Then the litter tray

Once illness has been ruled out, the tray is the most common explanation. Go through it point by point:

If the cat wees on the bed, on clothes or on the sofa, it may mean it prefers a soft surface and is not happy with the tray. Try a finer litter and more of it³.

Weeing or marking?

These are two different behaviours. When a cat wees, it squats and leaves a puddle, usually on a horizontal surface. When it marks, it stands with its tail raised and sprays a small amount of urine on a vertical surface, such as a wall or door frame⁵. Marking is a natural way of claiming territory. Neutering does not always solve it, because neutered cats can mark too. Indoors, marking is often a sign of insecurity, and it is more common in households with several cats¹. Marking can also be caused by an inflamed bladder⁴, so the vet is needed here too.

Stress, the common thread

Stress can be behind it in two ways at once. A new neighbourhood cat, a cat sitter or building work can both make a cat wee in the wrong places and trigger bladder inflammation that needs treatment from a vet¹. Common sources of stress include cats that do not get on, moving house, a new pet or family member, too few trays and too little to do⁴. That is why the environment and the urinary tract are linked, and why changing the litter is rarely enough on its own.

When to see the vet

Urgently, straight away, if your cat goes to the tray repeatedly and nothing or only a few drops come out, or if it seems to be in pain, vomits or becomes lethargic. If the cat cannot wee at all, see a vet immediately².

Within a couple of days if a previously house-trained cat has started weeing outside the tray, if you see blood in the urine or if the cat is drinking more than usual. The vet examines the cat and takes a urine sample, and sometimes an ultrasound or X-ray is needed³. Bring a urine sample if you can, and a note of when and where it has happened.

What you can do yourself

Clean the spot thoroughly. The smell draws the cat back. Wash it away properly and avoid strongly scented cleaning products.

Change the trays one thing at a time. Start with number and size, then litter and position. If you change everything at once you will not know what helped, and the cat gets yet another change to cope with.

Increase water intake. Wet food instead of dry food only, more water bowls and ideally a water fountain. Diluting the urine is part of the vet's treatment of idiopathic cystitis⁴.

Reduce competition. If you have several cats, make sure none has to pass another to reach the tray, the food or the water. Give each cat its own safe spot up high.

Never punish. A cat that is frightened at the tray or where it has weed becomes more insecure, not less.

Frequently asked questions

Why is my cat weeing on the bed?

Often because the bed is soft and smells safe, and because something about the tray does not suit it. But a cat with a painful urge can also choose the bed. Let the vet rule out urinary problems first.

Is my cat weeing outside the tray out of spite?

No. Cats do not wee in the wrong place to get revenge. It is about illness, discomfort at the tray or insecurity.

Will my cat stop marking if it is neutered?

It may decrease, but neutering is not always the solution. Neutered males and females can urine mark too, especially in households with several cats¹.

Can I wait and see if it passes?

Not if the cat seems desperate to wee without producing anything. It may be a urinary blockage, which is life-threatening². Otherwise, book an appointment within a couple of days.

That was the short answer. If you have a question about your own pet, email us at info@herbiovet.se. We reply within one working day.