Quick answer
Blood in cat urine always needs a vet visit, usually within a day. The most common cause is feline idiopathic cystitis, a painful bladder inflammation often linked to stress, followed by bladder stones and infections. If your cat is straining and producing little or no urine, especially a male cat, it may be a urinary blockage and is an emergency.
A blocked cat can die within a day or two without treatment. If you’re unsure, go now. Our should I go to the vet check can also help you sort out how urgent it is.
What causes blood in cat urine?
Blood in cat urine (the medical term is hematuria) most often comes from a problem in the bladder or urethra, the lower urinary tract. Vets group these problems as feline lower urinary tract disease, or FLUTD. The signs look similar whatever the cause, so tests are needed to tell them apart.
| Cause | Common signs | Urgency |
|---|---|---|
| Feline idiopathic cystitis (FIC) | Young to middle-aged cat, frequent small pees, often after stress | See vet soon |
| Bladder stones or crystals | Blood, straining, peeing often, sometimes recurring | See vet soon |
| Urinary tract infection | Blood, straining, strong smell, more common in older cats | See vet soon |
| Urethral blockage | Straining with little or no urine, crying, vomiting | Emergency |
| Injury | After a fall or road accident, pain, bruising | Emergency |
| Clotting problem or rat poison | Bleeding from other places too, pale gums, weakness | Emergency |
| Bladder tumor | Older cat, signs that keep coming back | See vet soon |
Feline idiopathic cystitis
“Idiopathic” means there’s no single clear cause. FIC is the most common diagnosis in cats with urinary signs. It’s linked to stress and to how a cat’s bladder and nervous system respond to it. Moving house, a new pet, conflict with another cat or a change in routine can trigger a flare.
Signs often settle within a couple of weeks, but they tend to come back. Cats with FIC need pain relief during flares, and reducing stress and increasing water intake help prevent the next one.
Bladder stones and infections
Struvite and calcium oxalate are the two most common stone types in cats. Some struvite stones can be dissolved with a prescription diet. Calcium oxalate stones can’t, and usually need to be removed.
Bacterial infections are less common than many owners expect in young cats. They’re more likely in older cats, especially those with kidney disease, diabetes or hyperthyroidism. Read more in our guide to cat UTI.
When is a cat peeing blood an emergency?
The key question is whether urine is coming out. A cat peeing blood that still passes normal-sized clumps in the litter is uncomfortable and needs a vet within a day. A cat that strains and produces little or nothing may be blocked.
Blockages are far more common in male cats, because their urethra is long and narrow. Crystals, mucus plugs or small stones can get stuck. Urine then backs up, toxins build in the blood, and potassium levels can rise enough to stop the heart.
Straining can look like constipation. If you’re not sure which it is, treat it as a possible blockage and go now. Our guide to urinary blockage in male cats explains the signs and treatment.
How will a vet find out what’s causing it?
Your vet will feel your cat’s bladder first. A large, hard bladder in a straining cat means a blockage until proven otherwise. After that, the usual tests are:
- Urinalysis: checks for blood, crystals, infection and how concentrated the urine is. Vets often collect a sterile sample with a fine needle straight from the bladder.
- Urine culture: confirms a bacterial infection and shows which antibiotic will work.
- X-rays or ultrasound: look for stones, thickening of the bladder wall or masses.
- Bloodwork: checks kidney function and other conditions, especially in older or blocked cats.
If the urine is normal apart from blood and nothing else is found, the diagnosis is usually FIC.
How much does it cost to treat blood in cat urine?
Costs depend on the cause and your area. These are typical ranges at a regular US clinic. Emergency clinics usually charge more, and treating a blockage costs much more than a standard visit.
| Service | Typical cost |
|---|---|
| Exam | $55 – $110 |
| Urinalysis | $50 – $120 |
| Urine culture | $80 – $175 |
| X-rays (2 views) | $150 – $350 |
| Bladder ultrasound | $250 – $500 |
| Unblocking and hospital stay | $1,500 – $4,000 |
For a detailed breakdown of blockage treatment, see cat urinary blockage surgery cost. For after-hours fees, see emergency vet cost for cats.
How can I help prevent it coming back?
Once your vet has found the cause and your cat is on treatment, these steps support urinary tract health, especially for cats with FIC or stones:
- Increase water intake. Wet food is the easiest way. Water fountains, several bowls and adding water to food also help.
- Feed any prescribed diet strictly. Urinary diets only work if your cat eats little else.
- Keep litter boxes clean and easy to use. One per cat plus one, scooped daily, in quiet spots.
- Reduce stress. Keep routines steady, give each cat its own resources and provide play, climbing and hiding places.
- Watch the litter box. Note how often your cat pees and how big the clumps are. Changes are an early warning.
Peeing blood is often painful, and your vet may send pain relief home with you. Use only that. Acetaminophen (paracetamol), ibuprofen and aspirin from your own cabinet are toxic to cats, and your vet will choose a cat-safe option and set the dose.
Some cats with urinary pain start peeing outside the box. If that’s happening, read our guide to a cat peeing outside the litter box, or browse more cat symptoms guides.
Frequently asked questions
Can blood in cat urine go away on its own?
Episodes of idiopathic cystitis often settle within a week or two, even without treatment. The same signs can come from stones, infection or a blockage, so your vet still needs to find the cause, and pain relief helps your cat in the meantime.
Is a cat peeing blood an emergency?
It's an emergency if your cat is straining with little or no urine, crying in the litter box, vomiting or very lethargic. Otherwise, book a vet visit for the same or next day.
Can stress cause blood in a cat's urine?
Yes. Stress is a well-known trigger for feline idiopathic cystitis, which is the most common reason for blood in the urine in young and middle-aged cats.
Sources
Written by the CatsMed Team from the sources above. This guide isn’t reviewed by a veterinarian and isn’t a substitute for one. See how we research.
