A 14-year-old 12.5-kg (27.5-lb) female mixed-breed dog with a recent diagnosis of hyperadrenocorticism and diabetes mellitus was evaluated as part of a recheck examination and because of lack of appetite, which had worsened in the last few weeks, and episodes of panting that lasted several hours. Further recent medical history included hind limb trembling and hospitalization for hypoglycemia-induced seizures. The dog vomited once while in the examination room. During recheck examination, muscle wasting and a decrease in proprioception in the hind limbs were observed, and the abdomen was tense on palpation. Findings of serum biochemical analysis were consistent with