A 4-year-old 29-kg (63.8-lb) spayed female Husky cross was evaluated by the emergency service of the Foster Hospital for Small Animals at Tufts Cummings School of Veterinary Medicine because of acute-onset collapse following cystocentesis by the referring veterinarian. Earlier that day, the dog had been examined by the veterinarian because of hematuria; on the basis of a suspected urinary tract infection, cystocentesis was attempted. The dog was manually restrained in dorsal recumbency for a blind attempt at cystocentesis; no sedatives were administered. A 1.5-inch, 22-gauge needle with an attached syringe was used, but the procedure was unsuccessful. Following the unsuccessful attempt, the dog was admitted for observation and further attempts at urine sample collection. Cystocentesis was attempted again later that day; the second attempt yielded a small amount of frank blood, and the third and final attempt yielded urine. The dog was reported as noncooperative and struggled during the procedures despite restraint. A presumptive diagnosis of a urinary tract infection was made, and the dog was discharged to the owner 1 hour later. The dog was apparently clinically normal at the time of discharge from the clinic.

During the journey home (approx 20 minutes after discharge from the clinic), the dog had an episode of collapse and was returned immediately to the primary care veterinarian for evaluation. The dog was weak and tachycardic. Results of in-house clinicopathologic testing performed at this time indicated that the PCV was 46%, blood glucose was 79 mg/dL (reference range, 82 to 117 mg/dL), and TP concentration was 5.0 g/dL (reference range, 6 to 7.2 g/dL), respectively. Blood urea concentration was 5 to 15 mg of urea/dL of blood, as determined by use of a reagent testing strip.^a An IV catheter was placed in the left cephalic vein, and 1.5 L (52 mL/kg [23.5 mL/lb]) of lactated Ringer's solution was administered as a bolus. The dog was referred for ongoing management.

On arrival at the hospital (within 20 minutes of leaving the primary care facility), the dog was recumbent with pale mucous membranes. The heart rate was 206 beats/min with bounding pulses; heart sounds were quiet. Respiratory rate was 40 breaths/min, and rectal temperature was 36.6°C (98°F). An abdominal fluid wave was detected by use of ballottement. A second IV catheter was placed in the right cephalic vein, and a sample of venous blood was obtained for assessment of PCV, blood TP and electrolyte concentrations, PT, and aPTT; blood gas analysis; CBC; serum biochemical analyses; and blood typing. Abdominal ultrasonography (performed by use of a portable machine) revealed marked peritoneal effusion; a sample of hemorrhagic fluid was removed via aspiration. At the initial evaluation, the dog's PCV was 24% and blood TP concentration was 1.2 g/dL; analysis of the abdominal fluid revealed that the fluid PCV was 20% and TP concentration was 1.2 g/dL. Results of point-of-care coagulation testing^b indicated that PT was 21 seconds (reference range, 12 to 17 seconds) and aPTT was 108 seconds (reference range, 71 to 102 seconds). The worsening anemia, hypoproteinemia, and prolonged coagulation times were consistent with massive blood loss and a mild dilutional coagulopathy. Blood gas and electrolyte abnormalities^c included hyponatremia (141.1 mmol/L; reference range, 147.0 to 154.0 mmol/L), hyperglycemia (120 mg/dL; reference range, 82 to 117 mg/dL), and hyperlactemia (6.5 mmol/L; reference range, 0.3 to 1.0 mmol/L). Ionized calcium concentration in blood was low (1.09 mmol/L; reference range, 1.17 to 1.38 mmol/L). These results were considered consistent with hemorrhage and associated hypovolemic shock.

Crystalloid fluid therapy was continued, and transfusion with packed RBCs was begun as the operating room staff was notified about the urgent need to perform an exploratory celiotomy for control of hemorrhage. On the basis of the severe hemoperitoneum and the close anatomic proximity of the aorta to the urinary bladder, an aortic laceration was suspected, although a large venous laceration could not be excluded. Two units of packed RBCs (18 mL/kg [8.2 mL/lb]) and 1 unit (9 mL/kg [4.1 mL/lb]) of FFP were transfused within 20 minutes. Because of worsening peripheral pulse quality and evidence of cardiovascular collapse, administration of lactated Ringer's solution was continued at 90 mL/kg/h (41 mL/lb/h). Other resuscitative techniques, including hypotensive resuscitation with early operative intervention, or administration of other types of fluids (eg, hypertonic saline or hetastarch solutions) could have been selected.

The dog was premedicated with hydromorphone (0.035 mg/kg [0.016 mg/lb], IV) and midazolam (0.2 mg/kg [0.09 mg/lb], IV), and anesthesia was induced via administration of propofol (2 mg/kg [0.9 mg/lb]). During surgery, mechanical ventilation was applied and anesthesia was maintained with isoflurane (0.75% to 1.5%) and bolus administration of hydromorphone (0.02 mg/kg [0.009 mg/lb], IV) intermittently. The dog's physical status was classified as 4-E (where E indicates emergency), according to the scheme adopted by the American Society of Anesthesiologists.¹

A ventral midline laparotomy was performed, and 2.2 L of blood was suctioned from the peritoneal cavity. The first 1.2 L of blood was collected aseptically in an autotransfusion device^d for later use. A large blood clot was seen in the caudal portion of the abdomen, with evidence of continuing bleeding dorsal to the blood clot. The abdominal aorta was located and confirmed to be the source of the bleeding. On inspection, a small pinprick and a 2-mm laceration were observed in the ventral surface of the aorta immediately dorsal to the urinary bladder; both defects were associated with severe hemorrhage. The aorta was occluded via application of digital pressure cranial to the defects, and the puncture and laceration were each oversewn with 4-0 polypropylene suture^e and packed with a cellulose-based hemostatic material.^f Occlusion of the aorta and application of digital pressure on the repair sites were maintained for a further 5 minutes, after which time the hemostatic material was removed, the aortic occlusion was released, and the repair sites were inspected for hemorrhage. The aorta was intermittently occluded for a total of 25 minutes during surgery. No further hemorrhage was evident, and the abdomen was closed in a routine manner. During surgery, the dog was administered physiologic saline (0.9% NaCl) solution (10 mL/kg/h [4.5 mL/lb/h]) along with 2 units of packed RBCs, 2 units of FFP, and autotransfusion of 1.2 L of blood that had been removed from the abdomen. Intraoperative point-of-care clinicopathologic analyses revealed that the dog's PCV was 19%, TP concentration was 2.2 g/dL, sodium concentration was 140.3 mmol/L, ionized calcium concentration was 0.85 mmol/L, and lactate concentration was 1.8 mmol/L. Because of progressive hypocalcemia, calcium gluconate (68 mg/kg [30.9 mg/lb]) was administered IV over a 5-minute period. The worsening hypocalcemia was thought to be associated with the transfusion of citrated blood products, including FFP, packed RBCs, and the autotransfused blood. Recovery from anesthesia was uneventful. The volume of blood products used was approximately 3 L (5 units of packed RBCs, 3 units of FFP, and 1.2 L of autotransfused blood).

Immediately after surgery, results of point-of-care clinicopathologic testing indicated improvement in the dog's condition; PCV was 23%, TP concentration was 3 g/dL, ionized calcium concentration was 0.97 mmol/L, lactate concentration was 1.7 mmol/L, glucose concentration was 100 mg/dL, and sodium concentration was 141 mmol/L. The PT and aPTT values were within reference limits. Heart rate was 77 to 126 beats/min, and systolic arterial blood pressure was 180 mm Hg (reference range, 90 to 140 mm Hg).² Administration of cefazolin (22 mg/kg [10 mg/lb], IV, q 8 h) and hydromorphone (0.05 mg/kg [0.023 mg/lb], IV, q 4 h) was commenced, and fluid therapy was changed to lactated Ringer's solution with 20 mEq of potassium chloride/L (3.8 mL/kg/h [1.73 mL/lb/h]). In addition, the dog received another dose of calcium gluconate IV. Intensive care monitoring included continuous ECG and assessment of urine output, blood pressure, and respiratory rate and effort; blood pressure rapidly returned to reference range, and all other monitored variables remained within reference limits during the postoperative period. The dog regurgitated some brown fluid during the first night following surgery.

The following morning, point-of-care clinicopathologic analyses revealed further improvement in the dog's condition; PCV was 28%, TP concentration was 3.4 g/dL, sodium concentration was 144.1 mmol/L, lactate concentration was 0.6 mmol/L, ionized calcium concentration was 1.26 mmol/L, and blood glucose concentration was 105 mg/dL. On physical examination, the only major abnormality was moderate to severe swelling of both hind limbs; signs of discomfort were evident on palpation of the hind limbs or when the dog attempted to stand. Administration of hydromorphone (for analgesia) and cefazolin (for treatment of a presumed urinary tract infection) was continued. To treat the suspected reperfusion injury, the dog received SAMe (23 mg/kg [10.5 mg/lb]) orally once daily. Because of regurgitation, administration of famotidine (0.7 mg/kg [0.32 mg/lb], IV, q 24 h) and omeprazole (0.7 mg/kg, PO, q 24 h) was initiated for treatment of possible esophagitis or gastrointestinal ulceration. All of the treatments were continued throughout the duration of hospitalization. At this time, the dog was markedly improved and signs of the hind limb discomfort and swelling were decreased; the dog was able to walk outside and eat without additional episodes of regurgitation.

The dog was discharged from the hospital on the third day after surgery. Bacterial culture of urine performed at the primary veterinary care facility yielded Enterococcus spp that were susceptible to several commonly used antimicrobials. The owners were instructed to administer potentiated amoxicillin (12.9 mg/kg [5.86 mg/lb], PO, q 12 h) for 14 days, tramadol (3.5 mg/kg [1.59 mg/lb], PO, q 8 h) for 3 to 5 days, and SAMe (23 mg/kg, PO, q 24 h) for 3 to 5 days. At the time of discharge from the hospital, the dog's PCV was 33% and TP concentration was 5.2 g/dL. The dog continued to do well but had an episode of vomiting and reduced appetite 2 days after discharge; treatment with potentiated amoxicillin was discontinued, and on the basis of the antimicrobial susceptibility test results, administration of enrofloxacin (9.4 mg/kg [4.3 mg/lb], PO, q 24 h) was commenced. Administration of famotidine and omeprazole was reinstated at the previous dosages. The dog continued to make a full recovery without further complications from this time point. At the time of suture removal, 10 days after surgery, the dog was clinically normal; PCV was 42%, and TP concentration was 6.0 g/dL. Bacterial culture of a free-catch sample of urine was performed and yielded negative results. Administration of all medications was discontinued.