INDUCTION AND MAINTENANCE OF GENERAL-ANESTHESIA IN SMALL ANIMAL PRACTICE

General anaesthesia in small animal practice consists of the administr ation of injectable or inhalant agents. Inhalant anaesthesia often fol lows an intravenous induction. Thiobarbiturates have the most traditio nal usage for short anaesthetic procedures or for induction. They have often been replaced by dissociative anaesthetics (ketamine) especiall y in the cat. One major advantage is the safe use of ketamine by intra muscular injection in difficult animals. Propofol, a new nonbarbiturat e anaesthetic, is the most recent addition to injectable selection. Re coveries from propofol are significantly improved over other injectabl es following prolonged anaesthesia. Many improvements are evident when newer inhalant anaestetics are compared to older agents such as dieth yl ether. Methoxyflurane provides excellent muscle relaxation and low risk to the cardiopulmonary system. Danger of overdose is minimum. It, however, has a higher metabolism rate than newer agents, thus potenti al for renal or hepatic toxicity is relatively high. Halothane current ly is a widely used inhalant. It causes a relatively higher cardiac se nsitivity with increased incidence of ventricular arrhythmias. Isoflur ane is a very safe anaesthetic with minimum metabolism. Cardiac arrhyt hmias are unlikely to occur. Enflurane has little advantage over isofl urane. Nitrous oxide usage is based on preference by the veterinarian and if its use to reduce requirements of more potent agents can contri bute to greater cardiac stabilization. The choice of an anaesthetic ag ent may depend on the type of practice and the available equipment. Mo dern veterinary practice can now include choices of equipment and anae sthetic agents to best meet the needs of each type of surgical practic e.