Yohimbine was studied at various dosages to examine its effectiveness in preventing xylazine-induced sedation and hyperglycemia in dogs.
An α₂-adrenergic blocking agent, yohimbine (0.05 to 0.50 mg/kg iv) was given fifteen minutes after injection of xylazine (2 mg/kg im) . Xylazine alone appeared to sedation, bradycardia, decrease of respiratory rate and hyperglycemia. These effects of xylazine were prevented by yohimbine. But, yohimbine at dosages of 0.25 to 0.50 mg/kg appeared to exitement, salivation and tachycardia for 30 to 60 minutes. In addition, effects of over dosage of xylazine (5 mg/kg im) were prevented by yohimbine (0.50 mg/kg iv) .
The results suggested that effects of xylazine are thought to be due to stimulation of α₂.adrenergic receptors and yohimbine can be used as an antagonist of xylazine. For this purpose, it seemed that yohimbine at dosages of 0.05 to 0.10 mg/kg is suitable.

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Anesthesia was induced by one hour's inhalation with enflurane or halothane at a concentration of 1 or 2%. There was no particularly remarkable difference in clinical signs shown under or after anesthesia, or in hematological findings after anesthesia between enflurane and halothane. Therefore, the two anesthetics were almost equivalent in the evaluation of clinical application.
Further investigations will be made in the following subjects : inhalation of an anesthesia at a high concentration; repeated anesthesia; effects upon the living body under anesthesia for a long time; clinical findings when some surgical stress is added to anesthesia; hematological findings; effects upon the cardiovascular and nervous systems.

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The preliminary study on the clinical use of enflurane anesthesia in 16 major surgeries of the dog has shown that type of inhalation anesthesia can be successfully and safty used follwing the induction of anesthesia either by enflurane inhalation from a mask or intravenous injection of thiopental sodium.
The average concentration of enflurane necessary for the maintenace of surgical stage was 2.4 percent (range: 1-3 percent) and no differance was found between two types of the induction used. After the maintenance of anesthesia as long as 95 minutes in most cases, the rapid recovery from anesthesia was obtained following the turning off of the anesthetic gas. All animals showed the pharynx-larynx reflexes within 4 minutes and started to walk after 10 minutes.
Although some mild time-dependent decline of the heart rate and the body temperature were observed during the anesthesia, the mean blood pressure and respiratory rate were maintained in very constant level a little lower than the normal range. No significant effect on kidney and liver functions was found as far as the post anesthetic serial determinations of GOT, GPT, LDH, ALP, urea nitrogen and creatinine in serum are concerened, Furthermore, any neurological problems such as muscular twitching and convulsions, which have been reported to appear occasionally in some species, were not seen in either of the inductions.

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A total of 96 dogs were subjected experimentally to surfacecooling low-body-temperature anesthesia by the method of Okamura et al. It was found out that to induce sufficient ether anesthesia was an especially important point in performing this method. Then studies were made on a correlation between the intensity of ether anesthesia and the amount of ether consumed or the velocity of inhalation of ether.
By using an evaporator of Wick type under autonomous respiration, ether with the addition of 0.5 mg/kg of triflupromazine was allowed to be inhaled slowly 5-10 minutes before introducing anesthesia with thiamylal sodium. As a result, the most satisfactory process of anesthesia was obtained when 1 ml/kg of ether was introduced for about 10 minutes, when a total of 2 ml/kg of ether was inhaled for about 20-30 minutes from the introduction to the time of dipping in ice water, and when a total of 3 ml/kg of eter was inhaled for about 40-60 minutes from the time of dipping in ice water to the end of treatment (when esophageal temperature was 25°C or below) . Many of the animals subjected to this process of anesthesia survived for a long time.

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The amounts of anesthetic gas used and changes induced in rectal temperature and heart rate were studied with anesthetic records obtained from 57 dogs and 29 cats GOF-anesthetized.
The results obtained are summarized as follows.
1. The amount of halothane (fluothane) (ml/kg⋅hr) used was below 2 in dogs and scattered from 0.2 to 9.0 in cats. It teneed to be larger in the cats than in the dogs.
2. In the analysis of the amount of halothane and the N₂O/O₂ total flow rate, the linear correlation coefficient was very significant in 15 male dogs (r=-0.79, p<0.01. The regression equation between them was y=-0.35x+1.34.
3. In each surgical procedure, especially in laparotomy, no changes in rectal temperature were indicated in curves. During anesthesia body temperature fell more distinctly in the cats than in the dogs, and in the lighter animals than in the heavier ones of both species.
4. During surgical anesthesia heart rate showed similar changes to those of body temperature. It was clarified that the lighter the body weight of an animal, the lower the heart rate of the animal.

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