Simple Field Anesthesia for Free-Ranging Microtines

Area of Science:

• Wildlife Biology
• Veterinary Anesthesia

Background:

• Physical restraint for microtine tagging can cause pain, stress, and reduce marking accuracy.
• Anesthesia may offer a humane and effective alternative for field-based microtine handling.

Purpose of the Study:

• To evaluate the efficacy of inhaled isoflurane for short-duration anesthesia in free-ranging voles.
• To assess if isoflurane anesthesia improves handling and marking quality during field procedures.

Main Methods:

• Twenty-four voles (Microtus and Myodes spp.) were anesthetized using two doses of isoflurane (0.2 mL) in a drop-chamber system.
• Procedures included subcutaneous passive integrated transponder tag injection and dorsal fur clipping.
• Induction and recovery times were recorded for each isoflurane dose.

Main Results:

• Median induction times were 54 seconds for the first dose and 50 seconds for the second dose.
• Median recovery times were 33 seconds for the first dose and 62 seconds for the second dose.
• No mortalities were observed during the study period.

Conclusions:

• Inhaled isoflurane in a drop-chamber system is a simple, inexpensive, and effective method for anesthetizing microtines.
• This technique minimizes stress and handling issues associated with traditional physical restraint.
• The study recommends isoflurane anesthesia for improved microtine tagging and marking in field settings.