Surgery on Tammar Wallaby (Macropus eugenii) Pouch Young

INTRODUCTION

Two features of marsupial young make them ideal for developmental studies: (1) Their immune system, like that of the thyroid and thermoregulation, develops relatively late after birth, and (2) they tolerate xenografts. This late development allows transplants to grow and survive in the recipient for at least 150 d without the use of immunosuppressants. The immaturity of the organ systems and the tiny size of the neonate pose difficulties for anesthesia. However, because the pouch young are completely heterothermic until at least 3 mo of age, cooling can be used as an anesthetic agent. In practice, however, we use hypothermia for neonates and young up to the age of 25-30 d, and injectable anethetics thereafter. Healing is remarkably rapid. This tolerance of xenografts and the ability and ease with which hypothermia can be applied to marsupial young provides a unique approach to understanding developmental processes that normally take place in utero in eutherians. This protocol describes surgical procedures and post-surgical care performed on tammar wallaby (Macropus eugenii) pouch young (PY).