[Clinical use of ketamine-xylazine for anaesthesia in the cat (author's transl)].

Based on experiences from anaesthesia of approximately 7000 cats in a four year period the effects of a combination of 20--25 mg/kg Ketamine and 0.5 mg/kg Xylazine given i/m are described. In the present study the Xylazine has been applied in considerably lower doses, compared with previous reports on these drugs, and this change has reduced the unwanted side effects, without at the same time reducing the effect on the muscular tension and the psychical disturbances induced by the Ketamine. Ketamine and Xylazine were given in one injection after being taken in the named sequence and mixed in the syringe. Indication for anaesthetizing the cats were, besides routine surgery in the out-patient clinic, operations of weakened animals for pyometra, foreign bodies, intestinal invaginations with and without resection, removal of abdominal tumors and urolithiasis. Animals with impared liver function were not anaesthetized with these drugs due to the important role of liver metabolism in their excretion. In spite of the fact that the corneal and laryngeal reflexes normally persist, the combination of the two drugs allowed surgery in these organs after application of local anaesthetics as an extra precaution. Premedication with atropine has not been used routinely, and still only very few cases of increased salivation or vomiting have been observed. Aspiration has not been a complication and in the whole material, only 3 deaths have occurred, none of them with a specific post mortem finding besides shock. In these 3 cases the patient died later than 45 minutes after the injection and after ended surgery. Side effects ascribed to phenomena of interaction have not been observed. One cat was anaesthetized a number of times during pregnancy without any effect on the cat or its kittens. It is concluded, that the Ketamine/Xylazine combination, when mixed as prescribed gives a very safe and pleasant narcosis, and that side effects are minimized, if the corneas are moistened with an ophthalmic ointment and the patient is allowed to recover in dark and quiet surroundings.