Summary: | Abstract Restraint of small mammals may be necessary for procedures such as attaching radio- collars or collecting blood samples. Additionally, when manual restraint is not sufficient, chemical restraint may be required to prevent injury to the animal and to the handler. However, the responses of mammals to chemical restraint are often either unknown or species-specific. We compared effects of 3 inhalant anesthetics (halothane, isoflurane, and methoxyflurane) and manual restraint on induction and recovery time, stress response, and hematological parameters in Arctic ground squirrels (Spermophilus parryii) in a field setting. Forty squirrels were live-trapped, randomly assigned to treatments, and released after recovery. Methoxyflurane (x:SE: 69.35.9 sec) had a greater induction time (ANOVA, P<O.OOl) than halothane and isoflurane, but isoflurane (19.5: 1.8) and halothane (9.2:0.8) did not differ. All anesthetics differed (P<O.OOl) in recovery times: methoxyflurane (198.0:21.0) had the slowest recovery time, isoflurane was intermediate (124.7:2.95), and halothane was the most rapid (66.4j:5.95). Time to immobilize and collect the blood sample with manual restraint took about twice as long (146.4: 11.4). Mean free cortisol levels (range: 81.5-91.8 nmol/L), glucose levels (range: 80.3-94.7 mg/dl), and hematocrits (range: 40.4-42.2%) were similar in all treatments; maximum corticosteroid binding capacity was greater (P<0.05) in squirrels anesthetized with halothane (125.8:3.87 nmol/L) than in other treatments (range: 100.3-118.8). We recommend using methoxyflurane for field use when portable anesthetic units are not accessible.
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