What this means
Blood in a cat's urine is not always plainly visible. Most often you notice it as a pink or brownish tinge, spots of blood or pink clumps in the litter, or a stain where the cat urinated outside the box. Pale or white litter helps you see it, while in dark litter a change of colour can be missed.
Blood in the urine only shows that something is irritating or damaging the urinary tract, and only a vet can find the cause. What matters most is whether the cat also strains to urinate, visits the box often or passes little urine. Then the danger is greater: the urinary tract may be blocked, a male cat's above all, and that can be life-threatening within hours.
Cats hide that they feel unwell, so blood in the urine is sometimes the only sign you can see. Do not wait for it to pass by itself or hope the next day will be better. Note when you first saw blood, whether the cat also strains to urinate and whether it is eating.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your cat.
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Bladder stones
Rough stones or grit irritate the bladder wall, which becomes inflamed and bleeds. A stone can also slip into the urethra and block it.
About the condition: Bladder stones -
Inflammation or irritation of the bladder
An inflamed bladder makes a cat visit the box often, and the urine may be pink. A vet finds the reason.
About the condition: Cystitis and FLUTD -
A blocked urinary tract
A plug in the urethra causes pain, straining and sometimes bloody urine. It is an urgent, life-threatening state, male cats above all.
About the condition: Urethral blockage -
Urinary tract infection
An infection can also irritate the urinary tract and bring blood. Only tests can tell it from the other causes.
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Injury or damage
A blow, a fall or another injury can damage the urinary tract. Bloody urine after an injury is a reason to seek help urgently.
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Other illness or a clotting problem
Blood in the urine sometimes points to another illness or a problem with blood clotting. Only a vet can find this out through tests.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- When you first saw blood, and whether there is more of it
- Whether the cat also strains to urinate or visits the box often
- How much urine comes and what the clumps look like
- Whether it cries while urinating or licks its genital area a lot
- Whether it is eating and drinking and not vomiting
- Whether blood spots turn up outside the box too
When to book a routine visit
Any bloody or pink urine needs a vet the same day. If the cat strains to urinate, go straight away.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Bladder stones Kidneys and urinary tract Hard, stone-like lumps of minerals that form in the bladder. They rub against its lining and make passing urine painful, and a stone or grit that slips into the urethra can block it completely, which is an emergency.
- Cystitis and FLUTD Kidneys and urinary tract Inflammation of the bladder, which makes passing urine painful and sends the cat back to the litter box again and again. In cats it does not only come from stones or infection: sometimes no clear cause is found, and the signs flare up after stress.
Body systems: Kidneys and urinary tract