The response of (laboratory) animals to anaesthetics and analgesics shows intraspecies variability. Besides environmental influences, genetic factors might be involved in this phenomenon. In the studies described in this book, rabbit and rat inbred strains were used to identify differences in response to anaesthetics and analgesics. Parameters for a genetic analysis were thus provided to identify candidate genes involved in this variability. Both in the rat and rabbit, significant strain differences were observed in the response to a variety of commonly used anaesthetics and analgesics in (laboratory animal) medicine. The difference in response to medetomidine between two rabbit strains was linked to differences in the anaesthetic's biotransformation rate. This response was then genetically analyzed and candidate genes were identified on the rabbit genetic map. In the rats it was demonstrated that buprenorphine administration did not only result in strain-specific responses to its analgesic but also to its behavioural effects. This book will aid medical and veterinary researchers in the development of tailored anaesthesia.