Actions and Dosage of Chloralose

Abstract

MANY books recommend chloralose as an anæsthetic for laboratory animals and give a dosage rate of 40–80 mg/kg body-wt.; the drug is considered particularly useful for animals in which autonomic reflexes are to be preserved. I have recently carried out a series of experiments in the dog and rabbit, and in no case did surgical anæsthesia result from intravenous injections of 70 mg/kg or less. If chloralose was used after induction with ether slight improvement was seen, but surgery was still not possible. The heart rate was slowed by 30 per cent in these experiments and excessive secretions caused respiratory embarrassment.