Signs to recognise
- In and out of the litter tray, producing a few drops or nothing
- Crying or straining in a posture that looks like constipation
- Constant licking of the genitals
- Blood in the urine
- Later: vomiting, lethargy, hiding, not eating
- A hard, ball-like bladder in the belly
Male cats have a narrow urethra and block completely; females usually get cystitis, block rarely, but still need treatment.
Why it is so dangerous
When urine cannot leave the body, potassium rises and stops the heart, and the kidneys fail acutely. Death can follow within 24 to 48 hours of a complete block. The sooner the block is relieved, the less kidney damage and the simpler the treatment.
What we do on arrival
- Confirm the swollen bladder, check potassium and kidney values, run an ECG.
- Stabilise the heart and start fluids.
- Pass a urinary catheter under sedation or anaesthesia, flush the bladder, and leave the catheter in for 1 to 3 days.
- Hospitalise with fluids, pain relief and antispasmodics, monitoring urine output and kidney values.
- Urine analysis and X-rays for crystals, stones and infection.
Most cats stay 2 to 4 days. Cats that block repeatedly may be offered a perineal urethrostomy.
Causes
- Idiopathic cystitis: the commonest, linked to stress and low water intake
- Crystals or stones (struvite, calcium oxalate)
- Urethral plugs of mucus and crystals
- Bacterial infection, mostly in older cats
Preventing a repeat
- More water: wet food, a fountain, several bowls, water added to dry food
- Urinary prescription diet to dissolve and prevent struvite, long term as advised
- Less stress: one tray per cat plus one, cleaned daily, hiding places, routine, pheromones
- Weight control: overweight indoor males are at highest risk
- Any cat that has blocked before should be checked the same day if urination looks abnormal
Cost
The cost of unblocking and hospitalisation depends on length of stay and kidney status. We give a written estimate as soon as the cat is stable and can discuss it in stages.