Blood in Cat Urine: Causes, Urgency and What the Vet Will Do

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Pink-tinged urine, or red spots in the litter, is alarming. The cause can be mild and self-limiting, or a medical emergency. The key is to look at the whole picture, not only the color, and to act quickly if your cat is straining.

Is it really blood?

Urine can be pink, red or brownish for several reasons. Clumps of litter that look reddish may be blood, but some litters, foods or medicines can change the color. Place a white paper towel or a non-absorbent litter in the box to check. If you are unsure, take a picture, and call the vet.

When it is an emergency

Go to a vet immediately if your cat:

• Strains in the litter box and passes little or no urine.
• Makes repeated trips with only drops of urine.
• Cries out, or licks its genitals constantly.
• Vomits, hides, is lethargic or has a swollen, painful belly.
• Is male. Male cats are at highest risk for blockage.

A blocked cat can die in one to three days. See signs of a urinary blockage in cats.

Causes

• Feline idiopathic cystitis. Inflammation of the bladder, without a clear infection or stones, often linked to stress. It is the most common cause in young to middle-aged cats. See feline idiopathic cystitis.
• Bladder stones or crystals. See bladder stones and crystals in cats.
• Urinary tract infection. More common in older cats and those with other diseases. See urinary tract infection in cats.
• Urethral blockage, from plugs or stones.
• Trauma, from an accident, or a fall.
• Tumors of the bladder or kidneys. See cancer in cats.
• Kidney disease, or high blood pressure.
• Clotting problems, such as from rat poison. See cat poisoning: what to do.
• Female reproductive tract, such as a uterine infection in unspayed females, or heat.

Associated signs

• Frequent urination in small amounts.
• Peeing outside the box. See why is my cat peeing outside the litter box and why does my cat pee on the bed.
• Straining or crying.
• Excess licking of the genitals.
• Strong-smelling urine.
• Increased thirst. See why is my cat drinking so much water.

Diagnosis

The vet will examine your cat, feeling the bladder, and collect urine, often by a needle through the belly wall, which gives a clean sample. Tests include urinalysis, culture and sometimes X-rays or ultrasound to look for stones or growths. Bloodwork checks kidney function and electrolytes, which are essential in a blocked cat. See cat blood tests explained.

Treatment

• Cystitis: pain relief, increasing water intake, a veterinary urinary diet, stress reduction and environmental changes. Most cases settle in a week or so, though they often recur.
• Infection: antibiotics.
• Stones: diet to dissolve certain types, or surgery.
• Blockage: emergency catheter, fluids and hospitalization, sometimes surgery.
• Tumors: depends on the type.

Prevention

• Encourage water intake with wet food and fountains. See cat water fountains: worth it and how to get a cat to drink more water.
• Keep litter boxes clean, with enough of them. See how often to clean a litter box.
• Reduce stress. See signs of stress in cats.
• Maintain a healthy weight.
• Feed the diet your vet recommends.

Idiopathic cystitis and stress

When no stones, infection or tumors are found, the diagnosis is usually feline idiopathic cystitis. The bladder lining becomes inflamed, probably through a link between stress and the nervous and hormonal systems. Signs often resolve within a week or so with supportive care, but can return. Environmental enrichment, multiple litter boxes, play, feeding puzzle toys and a calm routine lower the risk. See signs of stress in cats.

Diet and water

Wet food increases water intake and dilutes urine, which helps with crystals and cystitis. Prescription urinary diets can dissolve some stones and reduce recurrence. Never change to a urinary diet without veterinary advice, since the right choice depends on the cause. See wet vs dry cat food.

Male and female differences

Male cats have a narrow urethra, and are more likely to become blocked. Females rarely block, but can have cystitis, infections and stones. Both sexes need prompt care. Neutered cats are not immune from problems.

When to see a vet

See a vet the same day for blood in urine, and immediately for straining. Use the US vet directory to find a clinic.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.