Studies on the Effect of Ketamine Hydrochloride on Dogs after Bleeding : I. Clinical Findings and Acid-Base Balance

An increase in heart rate and no changes in respiratory rate and body tem-perature were observed in lnealthy dogs during ketamine anesthesia. As compared withthese dogs, bled dogs showed a low degree of increase in heart rate, a significant decreasein respiratory rate, and no change in body temperature during ketamine anesthesia. Inbled dogs, hematocrit; hemoglobin, and serum protein values remained unchanged duringketamine anesthesia, but increased at recovery. On the other hand, they decreased duringketamine anesthesia. In healthy dogs no acid-base balance was appreciably affected byadministration with ketamine. After bleeding, however, mild mixed acidosis was inducedby administration with ketamine. In phlebotomized dogs, ketamine anesthesia prolongedthe duration of anesthesia by about 15 minutes and produced more remarkable adverseeffects than in non-bled dogs after anesthesia. A few days after recovery from ketamineanesthesia following bleeding, vigor and good appetite were restored in the animals.It was concluded that administration with ketamine hydrochloride (30 mg per kg ofbody weight) to dogs after bleeding of such amount of blood as equivalent to 2 percentof body weight might be safe, but that due consideration should be given on the respira-tory function and the dosage of the drug.