blue juice
n.— «Often, a pre-sedative injection of ketamine or some isofluorane gas is used to let the ferret doze off so they cannot feel the final step. The final step may be an intravenous injection of an overdose of a sedative or barbiturate (such as “blue juice” or “euthanol”).» —“Dealing With The Loss Of A Ferret” by Erika Matulich Ferret Lovers’ Club of Texas (Dallas) Mar., 1998. (source: Double-Tongued Dictionary)