Summary: The aim of this study was to investigate the effects of general anaesthesia obtained by the combination of medetomidin, propofol and ketamine on their anaesthetic properties, cardiovascular and respiratoric system. The material was consisted of 7 dogs. Following 10 $mu$ g/kg administration of medetomidine, the combination of propofol 3.5 mg/kg and ketamine 10 mg/kg were injected intravenously for each animal and therefore general anaesthesia induced. ECG assessment, heart rate, respiratoric rate, body temperature and some blood parameters were evaluated for all animals before and after premedication at 5th minutes, during anaesthesia at 15, 30 and 60 minutes. Hematological analyses, including erytrocytes and leucocytes counts, hemaglobin and hematocrit values were carried out in 5 ml blood sample taken at each interval of the anaesthesia. The sedative and analgesic effect of the agents were evaluated as to the positioning of the animal, sensitivity to environmental objects and the reflex against pin needle, pedal, palpebral and pupillar. Decrease in rectal temperature and bradycardia were noted throughout the anaesthesia. Similarly, following the administration of the anaesthetic agent, decrease in respiratoric rate for all animals and temporary apnea were observed for 3 dogs. No abnormal ECG findings were obtained for all animals except sinus bradycardia and arrthy'mia during the anaesthesia between 5 to 60 minutes. Sedative effects of the premedicant agent commenced within two minutes. However, deep anaesthetic effect started approximately in 8 minutes. The recovery time was recorded between 68 to 100 (mean 86.1) minutes. Non-significant alterations were obtained between hematocrit, hemaglobin values and erytrocytes and leucocytes counts during the anaesthesia In conclusion, the anaesthetic agent combinations used in the present study was found to have a reliable anaesthetic properties except causing temporary cardiac and respiratoric problems in some dogs.