A previously healthy, 3-year-old 5-kg, castrated Siamese cat was presented for a 3-day history of stranguria.

HISTORYThis indoor-only cat, which had been adopted 2 years earlier, was visiting the litter box frequently but only producing a small amount of urine. In addition, he had been grooming and licking his perineal region excessively. His vaccinations were up-to-date. Two dogs also lived in the household.

CLINICAL PRESENTATIONThe cat appeared bright, alert, and responsive with a body condition score of 4/5. His rectal temperature was 103.7°F, heart rate 210 beats/min with strong pulses, and respiratory rate 70 breaths/min. Thoracic auscultation disclosed no abnormalities. Abdominal palpation revealed a small, painful urinary bladder. Swelling and erythema were noted on the prepuce and penis. Digital rectal examination was unremarkable.

LABORATORY DIAGNOSTICS

Urinalysis (Table and Figure 1) was conducted on a free-catch urine sample obtained from a clean litter box filled with nonabsorbent substrate. Bacterial culture of a urine sample obtained by cystocentesis was negative after 48 hours. The CBC and serum biochemical panel findings were within reference intervals.