A 13-year-old 5.5-kg (12.1-lb) castrated male Miniature Schnauzer was evaluated for a 2-day history of inappetence and an instance of vomiting 1 day before examination. The owner reported that diabetes mellitus had been diagnosed in the dog 3 years earlier and that since then, the dog had persistent polyuria and polydipsia. In addition, the dog had had an episode of diabetic ketoacidosis, pancreatitis, and a urinary tract infection 6 months before the present examination.
On physical examination, the dog had a grade 3/6 left apical heart murmur. The dog's abdomen had a tucked-up appearance and was tense on palpation,