⚠ Male Cat Blocked? This is an Emergency.
A male cat that is straining to urinate but producing no urine (or only a few drops) must be seen immediately. Urethral obstruction causes acute post-renal azotemia, hyperkalemia, and cardiac arrhythmias within 24-48 hours. Without relief, the cat will die. Do not delay — a blocked cat needs bladder drainage within hours, not days.
Overview
FLUTD is not a single disease — it is a clinical syndrome with multiple possible underlying causes. The causes in order of prevalence: Feline Idiopathic Cystitis (FIC) (~60-65% of cases) — sterile bladder inflammation of unknown cause; Urolithiasis (~15-20%) — mineral crystal aggregates (struvite or calcium oxalate) in the bladder or urethra; Urethral Plug (~10-15%) — matrix-crystalline obstruction at the urethral tip in male cats; Bacterial Urinary Tract Infection (~5-10%) — more common in older cats (>10 years) and those with diabetes or renal disease. FIC is a diagnosis of exclusion: no identifiable cause found after complete workup. The pathogenesis is complex — involving urothelial dysfunction, stress, and the neuroendocrine system. Multimodal environmental modification (MEMO) is the cornerstone of FIC management. Recurrence rate is high — up to 50% within 1-2 years without behavioral/environmental intervention.
Common Clinical Signs
Diagnostic Approach
| Diagnostic Test | Interpretation |
|---|---|
| Urinalysis (Cystocentesis) | Hematuria (microscopic RBCs) in most FLUTD cases. Crystals: struvite or calcium oxalate — identify the stone type for dietary management. Pyuria (>5 WBCs/hpf) suggests UTI — submit for culture. Proteinuria on dipstick should be quantified with UPC. No significant bacteriuria in FIC by definition. |
| Urine Culture (Cystocentesis) | Essential in cats >10 years, cats with diabetes or renal disease, or where infection is suspected. Culture before antibiotics if possible. Positive culture requires treatment with appropriate antibiotics based on AST. |
| Abdominal Ultrasound | Bladder wall thickening (>3mm) consistent with cystitis. Uroliths visible as hyperechoic structures with acoustic shadowing. Sediment in the bladder (blood, crystals). Allows assessment without invasive procedures. |
| Survey Abdominal Radiographs | Rocks: radiopaque stones (calcium oxalate) visible on plain films. Struvite stones are also radiopaque but may be smaller. ~85% of uroliths are radiopaque — radiographs are a useful first-line imaging tool. |
| CBC / Serum Chemistry | For non-obstructed cats: usually normal. For obstructed cats: azotemia (elevated BUN, creatinine), hyperkalemia (can cause bradycardia — check ECG), metabolic acidosis. Monitor electrolytes q6-12h in obstructed patients. |
| Cystoscopy / Urethroscopy | Rarely needed but can identify urethral strictures, polyps, or neoplasia. Requires general anesthesia and specialist equipment. Reserved for refractory cases or suspected neoplasia. |
Differential Diagnoses
- Bacterial urinary tract infection — The most important to rule out since it requires specific antibiotic treatment. Culture is the diagnostic test. More common in older cats and those with comorbidities (diabetes, CKD).
- Urolithiasis (stones) — Struvite uroliths (dissolvable with acidifying diet) vs calcium oxalate (not dissolvable — require surgical removal or urohydropulsion). Urinalysis and imaging differentiate stone type.
- Urethral Neoplasia — Transitional cell carcinoma (rare in cats) or polyps. Usually middle-aged to older cats with progressive obstruction. Ultrasound or contrast urethrography for diagnosis.
- Renal failure (acute or chronic) — Azotemia without lower urinary tract signs (no dysuria). USG would be dilute in renal failure vs FIC where USG is often concentrated.
Treatment & Management
Obstructed male cats: Urinary catheterization under sedation/anaesthesia + continuous bladder drainage for 24-72 hours. IV fluid therapy to correct azotemia and electrolyte abnormalities. Analgesia (buprenorphine, fentanyl patch). Monitor potassium and renal values until normalized. Unobstructed FLUTD: Analgesia (NSAID if renal function normal, or buprenorphine). Antispasmodics (prazosin) to relax the urethral sphincter. FIC long-term management: Multimodal Environmental Modification (MEMO) is the single most effective intervention: multiple litter boxes in quiet locations, daily scooping, low-stress environment, Feliway (feline facial pheromone), enrichment (play, vertical space), canned urinary diet (increases water intake and dilutes urine). Dietary management with urinary-formula canned food is key.