Harley, a spayed pug (12 years of age) weighing 9.6 kg, presented on emergency for an acute onset of restlessness and hyperexcitability, a tremoring episode, and polyuria/polydipsia of several days’ duration. Harley had a previous medical history of a cough of 6 months’ duration presumed to be caused by chronic bronchitis and had been diagnosed with pneumonia based on recent thoracic radiographic findings. Otherwise, she had been in good health. Harley was treated for the pneumonia and chronic cough with a tapering course of prednisone currently at 2.5 mg q24h (0.26 mg/kg), enrofloxacin 136 mg q24h (14.16 mg/kg), and theophylline 100 mg q12h (10.4 mg/kg). She had been receiving theophylline for several months and was started on prednisone and enrofloxacin within the previous week.