The use of inhalation anesthetics in large animals is increasing, especially for prolonged procedures. Advantages of inhalation anesthetics include their elimination mainly through the respiratory tract, the fact they do not accumulate during long procedures or require extensive metabolism for termination of their effects, and their maximum effectiveness and safety, provided that appropriate adaptations are made for fasting and positioning of ruminant animals (1). Sedation and induction of inhalation anesthesia are very important in large, aggressive animals. Xylazine is one of the α 2adrenoceptor agonists that are potent analgesics and reduce the minimum alveolar concentration of inhalational agents (1). Ketamine is a short-acting dissociative that produces anesthesia with moderate analgesia (2). Xylazine and ketamine have been used for premedication and induction in large animals (3,4). Although descriptions of general anesthetic techniques with isoflurane are readily available for animals (1,4,5), no information has been published that evaluates isoflurane for dromedary camels. Therefore, the aim here was to evaluate isoflurane as an inhalation anesthetic in dromedary camels after premedication with xylazine and induction with ketamine. 2. Materials and methods The experimental protocol was approved by the Ethics Committee for Animal Research, Scientific Research Deanship, Qassim University, Saudi Arabia. Food and water were withheld for 48 h and 24 h respectively for 6 healthy adult female dromedary camels (mean body weight = 378 kg, range = 321-503 kg; mean age = 7 years, range = 5-12 years). Sixteen-gauge intravenous (IV) and 20-gauge intraarterial catheters (Mais Co., Riyadh, Saudi Arabia) were placed in the left jugular vein and auricular artery (occasionally the radial artery), respectively, after surgical preparation and local infiltration of skin with 1 mL of lidocaine. Camels were premedicated with

Objective was to evaluate halothane as an inhalation anaesthetic after premedication with xylazine and induction with ketamine in camels. Six healthy, adult female dromedary camels were used as prospective controlled study. Camels were premedicated with xylazine (0.2 mg/kg, IV). Twenty minutes later, anaesthesia was induced with ketamine (2 mg/kg, IV) and was maintained with halothane in 100% oxygen. Onset and duration of anaesthesia were recorded. Rectal temperature, respiratory rate, heart rate, oxygen haemoglobin saturation, and systolic, diastolic, and mean arterial blood pressure were measured before and 20 min after administration of xylazine and then every 10 min until recovery. Lead II electrocardiogram was used to constantly monitor camels for presence of arrhythmias. Depth of anaesthesia was determined by recording reflexes. Venous and arterial blood samples were taken for haematological examination and blood gases and pH, respectively, at the same intervals. Results revealed a significant decrease in respiratory rate after xylazine and ketamine administration and significant decrease in rectal temperature and arterial blood pressure during halothane anaesthesia. A noticeable increase in the heart and respiratory rates was observed during halothane anaesthesia if compared to xylazine/ketamine values. However, the percentage of oxygen haemoglobin saturation and arterial pO 2 increased significantly with significant decrease in arterial pH during halothane anaesthesia. There were non-significant changes in the CBC values. The quality of anaesthesia was good in the majority of camels and recovery ranged from marginal to excellent. In conclusions, halothane resulted in good maintenance of anaesthesia and marginal to excellent recovery in dromedary camels. Precautions should be taken to avoid ruminal regurgitation. Oxygen administration is recommended during early recovery.