Why this is urgent
A urethral blockage prevents the cat from passing urine. Urine backs up. Within 24-48 hours, toxins build in the blood, potassium spikes, the kidneys fail, the heart can stop.
Male cats are at much higher risk than females because their urethra is long and narrow — a small crystal or plug can block it completely.
Signs
Clear signs of blockage:
- Repeated trips to the litter tray with nothing (or very little) coming out
- Straining in the litter box, often crying or vocalising
- Licking their genitals excessively
- Blood visible in the litter
- Restlessness, unable to settle
Later signs (emergency worsening):
- Vomiting
- Lethargy or collapse
- Hiding
- Cold body temperature
- Not eating
What's happening
Partial or complete obstruction of the urethra — usually by:
- Urinary crystals or stones (struvite, calcium oxalate)
- Mucous plugs from inflammation (feline idiopathic cystitis)
- Urethral spasm
What to do
Go to a vet immediately. Now. Tonight. Whatever time it is.
- Do not wait to see if it resolves.
- Do not try home remedies.
- Do not give any medication.
If you don't have a regular vet available, find the nearest emergency clinic.
Treatment at the vet
- Immediate stabilisation (IV fluids, pain relief, correcting potassium)
- Urinary catheter placed under sedation to relieve the obstruction
- Hospitalisation (usually 2-4 days) with IV fluids until the cat is urinating normally
- Investigation of the cause (urinalysis, imaging) and prevention plan
Cost is significant (often £1,500-£3,000+ in the UK, AUD $3,000-$6,000 in Australia), and recovery is usually excellent if treated promptly.
Prevention for at-risk cats
If your cat has had a previous blockage or has feline lower urinary tract disease:
- Prescription urinary diet (Hill's c/d, Royal Canin Urinary SO)
- Wet food (increases water intake)
- Multiple water stations, fresh water daily
- Reduce stress (FeLIWAY diffusers, enrichment, multi-cat household management)
- Regular vet check-ups with urinalysis
A hard truth
Male cats who have had one blockage are at risk for another. Some cats have recurrent episodes despite best management — in severe cases, a "perineal urethrostomy" (surgery to widen the urethral opening) may be recommended.
But right now, if your male cat is straining and nothing is coming out: go.