SEDATIVE EFFECTS OF MIDAZOLAM IN RED-EARED SLIDER TURTLES (TRACHEMYS-SCRIPTA ELEGANS)

Chelonians frequently require anesthesia br sedation to permit perform ance of clinical procedures. Midazolam is a safe and reversible benzod iazepine used in many other species for its sedative and muscle relaxa nt properties. The objective of this study was first to determine an e ffective dose of midazolam in red-eared slider turtles (Trachemys scri pta elegans) and then to examine the extent and duration of the effect s of this dose on those same turtles. In the first part of the study, 12 turtles were given increasing doses of midazolam intramuscularly at 5-min intervals until a cumulative dose was reached that allowed manu al extension of the head and neck and opening of the mouth without res istance. The effective dose at which 10 of the 12 turtles were thus se dated (ED(80)) was 1.5 mg/kg i.m. This dose was then administered as a single i.m. injection to eight of the same turtles 3 wk later in the second phase of the study. Two other turtles were injected with saline as controls. The onset time, duration of sedation, and recovery time were measured; the medians were 5.5 min (range = 4-28 min), 82 min (ra nge = 3-114 min), and 40 min (range = 20-60 min), respectively. Neithe r respiratory nor heart rates were affected by sedation. Although much individual variability in response to midazolam was found, midazolam appears to be an effective and safe sedative in red-eared slider turtl es.