Acute pulmonary oedema and electrocardiographic changes following ketamine administration in a crossbreed dog

A 3-year-old male crossbreed dog presented with 1-week history of external otitis. During the initial clinical examination, the dog appeared alert and bright and there was no sign of other abnormalities. Ketamine was administered intramuscularly to induce a light sedation in order to perform otoscopic examination. Fifteen minutes following ketamine administration, the dog showed severe respiratory distress. Thoracic auscultation and radiography revealed the occurrence of pulmonary oedema secondary to adverse side effects of ketamine injection. Electrocardiographic findings showed low-voltage QRS complexes which continued, monitored via electrocardiograms, over the clinical course of the respiratory distress. This eletrocardiographic pattern disappeared completely the following day concurrent with the resolution of any respiratory distress. In view of the widespread use of ketamine by veterinary surgeons, the aim of this report is to contribute towards an increased awareness relating to unusual secondary cardiorespiratory effects of ketamine within the veterinary practice.