What Is Your Diagnosis?

Abstract

HistoryA 4-year-old 6.8-kg (15-lb) neutered male Abyssinian cat was referred because of a 1-week history of anorexia and lethargy. The cat had previously received dexamethasone (0.5 mg/kg [0.23 mg/lb], SC, q 24 h), enrofloxacin (5 mg/kg, [2.3 mg/lb], SC, q 24 h), and IV fluid therapy with saline (0.9% NaCl) solution at a rate 30 mL/kg/h (13.6 mL/lb/h) for the first 8 hours, then 3 mL/kg/h (1.4 mL/lb/h) for 4 days. Urine output was estimated to be low by the referring veterinarian.Physical examination revealed hypothermia (body temperature, 33°C [91.4°F]), a heart rate of 190 beats/min, no heart murmur, weak femoral pulses, slow capillary refill time, tachypnea (60 breaths/min), expiratory dyspnea, diffuse harsh lung sounds, and an abdominal fluid wave.Hematologic evaluation revealed mature neutrophilia (18.3 X 10 9 neutrophils/mL; reference range, 3 X 10 9 neutrophils/mL to 12 X 10 9 neutrophils/mL). Serum biochemical analysis revealed high alanine aminotransferase activity (2,227 U/L; reference range, 10 to 90 U/L) and urea nitrogen concentration (24 mmol/L; reference range, 5.4 to 10.7 mmol/L). Serum lactate concentration was moderately high at 5.9 mmol/L (reference range, 0.4 to 2.5 mmol/L 1 ). The cat had mild hypoalbuminemia, mild hyperbilirubinemia, mild hypocalcemia, hyponatremia (130 mmol/L; reference range, 145 to 158 mmol/L), and hyperkalemia (5.1 mmol/L; reference range, 3.6 to 4.9 mmol/L).Venous blood gas analysis revealed probable mixed metabolic acidosis and respiratory alkalosis, given a pH of 7.21 (reference range, 7.35 to 7.45), base deficit of 11 (reference range, -4 to 2), and PCO 2 of 31.8 mm Hg (reference range, 38 to 51 mm Hg). Systolic arterial blood pressure measured by Doppler ultrasonography was 80 mm Hg (reference range, 110 to 160 mm Hg).Abdominal ultrasonography revealed free abdominal fluid that was subsequently characterized as a modified transudate (total solids concentration, 23 g/L; specific gravity, 1.020), hyperechoic renal cortices, and a medullary rim sign. Thoracic radiographs were obtained (Figure 1).Determine whether additional imaging studies are required, or make your diagnosis from Figure 1-then turn the page →