A 6-year-old sexually intact male Labrador Retriever was referred for surgical evaluation after being hit by an automobile earlier the same day. The dog was initially treated by the referring veterinarian with lactated Ringer's solution (1 L, IV bolus) for cardiovascular support. The dog was also treated with morphine (0.7 mg/kg [0.32 mg/lb], IM) and diazepam (0.3 mg/kg [0.14 mg/lb], IV) for signs of pain and to provide sedation. Multiple pelvic fractures were detected on radiographs obtained by the referring veterinarian.
On physical examination, the dog was cardiovascularly stable with a normal sinus rhythm as determined by ECG. Blood