Symptoms

Why is my cat peeing outside the litter box?

Updated 2026-07-16 · Not a substitute for professional veterinary care

Can signal an emergency

Short answer

It is usually a medical or stress signal, not spite. Causes range from urinary infections and crystals to kidney disease, diabetes, arthritis, or litter-box aversion. One pattern is a true emergency: a cat, especially a male, straining and producing little or no urine may have a blocked bladder, which is fatal within a day or two. That needs an emergency vet now.

The emergency to rule out first

If your cat is going in and out of the box, crouching and straining, crying, and passing only drops or nothing, treat it as an emergency. A blocked bladder (urethral obstruction) is most common in male cats and can cause kidney failure and death within 24 to 48 hours. Go to an emergency vet immediately. Do not wait to see if it passes.

Medical causes when there is no blockage

Urinary tract inflammation or infection (frequent, painful, small pees)
Bladder crystals or stones
Kidney disease or diabetes (larger volumes, more often, more thirst)
Arthritis pain making a high-sided box hard to enter, common in older cats

Because so many causes are medical, a vet check comes before assuming it is behaviour.

Litter-box and stress causes

A dirty box, or too few boxes (the rule of thumb is one per cat plus one)
A new litter, scented litter, a covered box, or a box moved to a busy spot
Stress from a new pet, person, move, or routine change
Territorial marking (small amounts on vertical surfaces)

What to do

If there is any straining with little urine, go to an emergency vet now.
Otherwise, book a vet visit to rule out a urinary or metabolic cause first.
Meanwhile, keep boxes clean, add a box, and try a large uncovered box with unscented litter.

When in doubt, call a vet. This guide is general information for cat owners. It is not veterinary advice, and it is not a substitute for professional veterinary care, diagnosis, or treatment. If your cat is in distress, contact a veterinarian or your nearest emergency clinic straight away.

Notice the quiet changes early

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Common questions

Is my cat doing this out of spite?

No. Cats do not urinate outside the box for revenge. It is almost always a medical issue, pain, or stress, so start with a vet check.

My male cat is straining and nothing comes out. What do I do?

Treat it as a life-threatening emergency and go to an emergency vet immediately. A blocked bladder can be fatal within a day.

How many litter boxes should I have?

One per cat plus one extra, in quiet, easy-to-reach spots, kept clean. Too few or dirty boxes is a common cause of accidents.

Sources

This guide draws on the following veterinary references: