Field anaesthetic and surgical techniques for implantation of intraperitoneal radio transmitters in Eurasian beavers Castor fiber
Ranheim, B., Rosell, F., Haga, H.A. & Arnemo, J.M. 2004: Field anaesthetic and surgical techniques for implantation of intraperitoneal radio transmitters in Eurasian beavers Castor fiber. - Wildl. Biol. 10: 11-15.
Radio transmitters were implanted intraperitoneally in 22 (nine females, 13 males) adult, territorial Eurasian beavers Castor fiber under field conditions. Two different injectable anaesthestic drug combinations were tested. Access to the peritoneal cavity was made through a ventral midline incision. The animals in group # 1 (N = 10) were initially injected with medetomidine (0.05 mg/kg), ketamine (5 mg/kg) and butorphanol (0.1 mg/kg). Three animals needed additional injections of the drug combination. Muscle relaxation was poor and variable and some of the animals were sound sensitive. When midazolam (0.25 mg/kg) was added to the drug combination (group # 2), muscle relaxation was excellent and the beavers (N = 12) did not react to sound stimuli. All surgeries were successfully performed. One animal in group # 1 died postoperatively due to circulatory failure. The behaviour and movements of the beavers did not appear to be affected by the procedure or the implant, except for the first few days when more time was spent inside the lodges. All beavers stayed in their original territory until they died, or as long as 17-24 months after the implantation. Based on these results, it appears that an injectable drug combination based on medetomidine, ketamine, butorphanol and midazolam and a surgical access through the ventral midline is suitable for implanting radio transmitters intraperitoneally in beavers under field conditions.
Key words: anaesthesia, Castor canadensis, Castor fiber, intraperitoneal implantation, radio-telemetry, surgery
Birgit Ranheim, Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, P.O. Box 8146 Dep., NO-0033 Oslo, Norway - e-mail: birgit.ranheim@veths.no
Frank Rosell, Faculty of Arts and Sciences, Department of Environmental and Health Studies, Telemark University College, NO-3800 Bø i Telemark, and Department of Zoology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway - e-mail: Frank.Rosell@hit.no
Henning Andreas Haga, Department of Large Animal Clinical Sciences, The Norwegian School of Veterinary Science, P.O. Box 8146 Dep., NO-0033 Oslo, Norway - e-mail: andreas.haga@veths.no
Jon M. Arnemo, Department of Arctic Veterinary Medicine, The Norwegian School of Veterinary Science, NO-9292 Tromsø, Norway and Department of Forestry and Wilderness Management, Hedmark College, Evenstad, NO-2480 Koppang, Norway - e-mail: jmarnemo@online.no
Corresponding author: Birgit Ranheim
Received 14 August 2002, Accepted 21 March 2003
Associate Editor: Heikki Henttonen