Endotracheal isoflurane anesthesia for chick auditory surgery

Survival surgeries upon chicks are commonly used in auditory research. Appropriate anesthesia is usually obtained with intramuscular or intraperitoneal injections of systemic agents. These techniques have several drawbacks, including delayed onset of anesthesia, difficulty in adjusting the dosage to accomodate individual animals' different responses, prolonged recovery times, and in some cases substantial mortality. We present a technique of administering inhaled isoflurane via an endotracheal tube which we have used for over a year with excellent results. With this agent, onset of deep anesthesia is very rapid, dosage can be titrated readily, overdosage is survivable, complete recovery occurs within a few minutes and mortality is rare. This technique may be valuable for other auditory scientists performing survival surgery in avian species.