A SPECIAL NOTE REGARDING MIXING ANAESTHETIC DRUGS PRIOR TO ADMINISTRATION: Question 14b of the IACUC protocol review form asks if “all drugs used for sedation, anesthesia, analgesia or euthanasia named in the protocol will be pharmaceutical grade”. In the opinion of The NIH Office of Laboratory Animal Welfare, the combination of anesthetics drugs which are otherwise pharmaceutical grade, is not considered to be pharmaceutical grade. In this case, the appropriate answer to question 14b is “NO,” and an appropriate reason for using the combination may be to minimize the number of injections that an animal will receive to attain an adequate level of anesthesia.