My male cat keeps straining in the litter box but no urine comes out — how urgent is this?
A male cat that squats repeatedly and produces no urine may have a blocked urethra — a condition that can become fatal within a day or two and needs immediate veterinary care.
A male cat’s urethra is narrow enough for crystals, stones, or inflammatory plugs to seal it completely. Owners often mistake the straining for constipation, and the hours lost to that mix-up are exactly the hours a blocked bladder cannot spare.
Why hours matter with a blocked bladder
Once urine cannot leave, pressure backs up into the kidneys and potassium climbs in the blood, disturbing the heart rhythm. Cats deteriorate from restless licking of the genital area and frequent empty squatting to vomiting, hiding, and collapse — sometimes within 24 hours. A hard, painful belly in a cat that has produced no urine is a late sign.
How fast potassium rises varies from cat to cat, so no owner can safely estimate the remaining margin at home. If a male cat has strained without producing urine for more than a few hours — or shows vomiting or lethargy on top — treat it as an emergency and take it to a veterinary hospital right away.
MediIndex articles are for general information only and are not medical advice, diagnosis, or advertising. Outcomes vary by individual — consult a board-certified specialist for personal decisions.