Objective To compare the anaesthetic and cardiopulmonary effects of alfaxalone in comparison to propofol when used for total intravenous anaesthesia (TIVA) during ovariohysterectomy in dogs. Animals Fourteen healthy female crossbred dogs between 6 months and 5 years, with body weight between 16 - 42 kg. Methods All dogs were premedicated with acepromazine 0.01 mg/kg and morphine 0.4 mg/kg subcutaneously. Anaesthesia was induced and maintained with either Group 1- propofol (6 mg/kg followed by 0.3-0.5 mg/kg/min intravenously) or Group 2 alfaxalone (2 mg/kg followed 0.10-0.12 mg/kg/min intravenously). Quality of induction and recovery were determined. Dogs were spontaneously breathing 100 % oxygen. Respiratory and cardiovascular parameters were measured: Respiratory rate (RR), end tidal CO2 (ETCO2), tidal volume (TV). Heart rate (HR), systolic (SAP), diastolic (DAP), and mean arterial blood pressure (MAP). Arterial blood samples were collected during and after the surgery to determinate arterial PH, PaCO2, PaO2. Results Smooth and rapid induction followed by satisfactory maintenance and good recovery quality was observed with both anaesthetic agents. Cardiopulmonary effects were similar for both groups with notable respiratory depression and fair hemodynamic parameters. Conclusions and Clinical Relevance The administration of alfaxalone used as TIVA in premedicated dogs produced satisfactory anaesthesia with the same quality as that produced by propofol during ovariohysterectomy. Hypoventilation was the most prominent adverse effect from both anaesthetic agents suggesting a need for ventilatory support during prolonged TIVA periods with either anaesthetic agent. / Dissertation (MSc)--University of Pretoria, 2010. / Companion Animal Clinical Studies / unrestricted