Glossary

FLUTD

An umbrella term for the conditions that cause pain, straining and bloody urine in a cat's bladder and urethra.

Also called: feline lower urinary tract disease, feline lower urinary tract signs, urinary tract disease in cats

FLUTD stands for feline lower urinary tract disease. It is not a single illness. It describes a group of problems in the bladder and urethra that all look much the same: straining to pass urine, passing small amounts often, crying in the litter box, blood in the urine, licking the genital area and urinating outside the box.

The most common cause in cats under about ten years old is cystitis with no obvious cause, which is linked to stress. Other causes include bladder crystals and stones, a plug of material in the urethra, infection, which is more common in older cats, and tumors or injuries. Because the signs overlap, owners cannot tell the causes apart, and a vet needs to examine the cat, test the urine and sometimes take X-rays or an ultrasound.

The urgent risk is a urinary blockage, which affects mostly male cats. A cat that strains and passes no urine, cries, hides or vomits needs a vet immediately. Even with milder signs, see a vet the same day, since a blocked cat can look the same as one with simple discomfort. Ask your vet about diet, water intake, a stress-free home and a plan for repeat episodes.

Last reviewed November 7, 2026

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Related terms

Cystitis Inflammation of the bladder, which in cats is often stress-linked and has no infection or stone behind it. Urinary blockage A life-threatening emergency in which the urethra is plugged so a cat cannot pass urine, most often in male cats. Bladder crystals Microscopic mineral particles in urine that can clump into stones and irritate or block a cat's urinary tract. Urinalysis A set of tests on a cat's urine that reveals kidney function, infection, crystals, diabetes and more. Chronic kidney disease A gradual loss of kidney function, common in older cats, that can be managed for months or years but not cured.

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