This is a comparative study of the aesthetic effects of Ketamine-Medetomidine and Tiletamine-Zolazepam-Medetomidine for the use in White-tailed Porcupines (Hystrix leucura).
Capture and anaesthesia of porcupines in zoos is often necessary for diagnostic and therapeutic procedures. Techniques currently used to chemically immobilize porcupines vary. In the past combinations of ketamin-xylazine and tiletamine-zolazepam have been described. In this study medetomidine-ketamin was compared to medetomidine combined with tiletamine-zolazepam.
Twenty immobilizations of white tailed porcupines (Hystrix leucura) were evaluated at the Landestiergarten Herberstein, Austria between June 2008 and June 2009. There were two groups (A,B) and each group consisted of 10 animals. Group A received 4,21 ± 0,66 mg/kg ketamine (Ketamidor®; Accreditation Richter Pharma AG, Wels, Austria) and 84,22 ± 13,13 μg/kg medetomidine (Domitor®; Producer Orion Corporation, Espoo, Finland; Distribution Pfizer, Vienna, Austria) and group B received 3,7 ± 0,4 mg/kg tiletamine-zolazepam (Zoletil®; Virbac Schweiz AG, Glattbrugg, Switzerland) and 37,03 ± 3,7 μg/kg medetomidine (Domitor®; Producer Orion Corporation, Espoo, Finland; Distribution Pfizer, Vienna, Austria). Anaesthesia was antagonized with 0,42 ± 0,07 mg/kg atipamezole (Antisedan®; Orion Corporation, Espoo, Finland) in group A and 0,21 ± 0,02 mg/kg atipamezole (Antisedan®; Orion Corporation, Espoo, Finland) and 0,01 ± 0,001 mg/kg sarmazenile (Sarmasol®; Producer Dr. E. Gräub AG, Bern, Switzerland) in group B, four animals of group B only got atipamezole. All drugs were administered with a blowpipe (Blow125®; Dan-Inject Dart Guns, Brenham, USA) into the gluteal muscles. During each 30 min procedure respiratory rate, heart rate, oxygen saturation, mucous membrane colour, capillary refill time, eyelid and corneal reflex, muscle relaxation, depth of anesthesia and core body temperature were evaluated every five minutes. Additionally, first reaction time, lateral recumbency, immobilization time, standing time and recovery time were recorded for each porcupine.
The main difference between group A (n=10) and group B (n=10) was observed during the recovery phase. The animals in group A had a smooth and uneventful recovery and could quickly be returned to the enclosure, the recovery time was 10:00 ± 08:25 minutes. Group A had an oxygen saturation of 77 ± 9,5% and group B 68 ± 9,5% and their recovery time was 01:08h ± 56:00 minutes with sarmazenile (n=6) and 52:15 ± 13:00 minutes without (n=4). The problem was, that these 4 animals without sarmazenile were only monitored until they awake for the first time and the re-asleep was not considered. During recovery animals of group B were anxious, disoriented, sneezing and some even seemed to have visual deficits. They also have a lower fear response to the presence of humans. The animals had to be kept separately in a box until they had recovered completely to avoid being attacked by other porcupines in the collection. The results of the study show that the combination of Ketamine-Medetomidine is a superior combination for the anesthesia of white-tailed porcupines in a captive setting.