Between 1996 and 2005, 215 free-ranging Alpine chamois (Rupicapra rupicapra) were immobilised with xylazine hydrochloride. The 110 male and 105 female animals received a mean (sd) dose of 2.5 (0.6) mg/kg with a range from 1.4 to 4.8 mg/kg. The immobilisation was reversed in 201 of the animals with an intramuscular injection of 0.3 (0.1) mg/kg atipamezole (range 0.03 to 0.76 mg/kg), corresponding to a mean ratio of atipamezole:xylazine of 1:9.4 (4.3). All the chamois were immobilised, but shorter induction and recovery times, and deeper sedation with no reactions to handling were obtained in more than 80 per cent of the animals with doses of 2.6 to 3.6 mg/kg of xylazine, reversed with 0.26 to 0.36 mg/kg atipamezole (a ratio of 1:10), injected within 90 minutes.

One-hundred and fifty-five free-ranging Northern chamois (Rupicapra rupicapra) were anaesthetised in the course of a restocking programme using xylazine plus ketamine. Mean±SD dosages for xylazine and ketamine were 1.9±0.5 and 2.2±0.7 mg/kg, respectively. In 57 chamois, sedation was reversed using 0.3 ±0.1 mg/kg atipamezole. Although all the anaesthetic dosages tested immobilised free-ranging Northern chamois, shorter induction times (4.8±2.6 min), deeper sedation with no reaction to handling in >90% of the animals and quick reversal (4.0±2.7 min) were obtained using 2.5 mg/kg xylazine plus 3.0 mg/kg ketamine reversed with 0.25 mg/ kg atipamezole. Under the conditions of this study, suggested standard doses are 63 mg/animal xylazine plus 76 mg/animal ketamine reversed by 6.3 mg/animal atipamezole. This anaesthetic protocol improves the results from the previous study of Dematteis et al. (Vet Rec 163:184-189, 2008) using xylazine alone.Keywords: Xylazine, Ketamine, Atipamezole, Chamois, Anaesthesia. IntroductionSeveral anaesthetic protocols have been used to immobilise chamois (Rupicapra spp.): ketamine plus medetomidine antagonised with atipamezole (Jalanka and Roeken 1990;Walzer et al. 1996Walzer et al. , 1998; etorphine plus acepromazine antagonised with diprenorphine (Wiesner et al. 1982); xylazine alone (Bauditz 1972;Gauthier 1993a; Peracino and Bassano 1993;Dematteis et al. 2008); xylazine plus carfentanyl antagonised with naloxone plus yohimbine (Duchamps 1985); xylazine plus fentanyl antagonised with naloxone plus yohimbine (Jensen 1982); xylazine plus ketamine (Wiesner and von Hegel 1985;Fico 1988;Moran et al. 1994;von Hardenberg et al. 2000) and tiletamine plus zolazepam (Chaduc et al. 1993). However, most of these studies did not evaluate physiological responses to treatment, and the suitability of tested drugs was mainly assessed based on observation, experience and anecdotal evidence.The aim of this retrospective study was to analyse dosages of xylazine-ketamine combination reversed by atipamezole in free-ranging Northern chamois in order to identify a specific and safe anaesthetic protocol. The drugs were analysed for their ability to achieve rapid and deep immobilisation and effective recovery safely. Furthermore, the possibility of administering a standard dosage irrespective of sex and body mass is discussed, since environmental operating conditions in the Alps hinder prompt adaptation of dosage to the characteristics of the individual target (Dematteis et al. 2008).Xylazine is an alfa-2-adrenergic tranquilizer used to immobilise wildlife both as a sole immobilising agent (Jorgenson et al. 1990(Jorgenson et al. , 1991Haviernick et al. 1998) and in combination with other anaesthetics (Delvaux et al. 1999;Kilpatrick and Spohr 1999;Janovsky et al. 2000). It has a large safety margin since its lethal level is more than ten times the normal dosage (Delvaux et al. 1999). Among its potential side effects, respiratory depression, rumen stasis and bradycardia may appear at high dosages (Jacobsen ...