Cardiorespiratory and neurological effects of morphine and butorphanol inBos taurus

Abstract

The temperament of Spanish fighting bulls precludes safe handling and necessitates chemical restraint as for wildlife species. A tiletamine-zolazepam-xylazine combination (TZX) is widely used in wild ruminants (Caulkett and others 2000). However, there is scarce information on the use of opioids, such as butorphanol or morphine in ruminants (Machado and others 1998, Fierheller and others 2004, Prado and others 2008). Atipamezole has been used successfully in ruminants to antagonise drug combinations including α2 agonists (Arnemo and Soli 1993, Rioja and others 2008). The present study was performed to evaluate the cardiorespiratory and neurological effects of butorphanol and morphine in Spanish fighting bulls during TZX anaesthesia antagonised with atipamezole. The study was approved by the Animal Care and Use Committee of the University of Cordoba (N° 719/2010). The study included 10 Spanish fighting bulls (5 males and 5 females) weighing 230±20 kg and aged 2±0.3 years. Each was anaesthetised using four different protocols administered in random order with a washout period of 10 days. The control protocol (C) consisted of tiletamine (0.5 mg/kg), zolazepam (0.5 mg/kg) (Zoletil 100; Virbac, Spain), and xylazine (1 mg/kg) (Xilagesic 20 per cent; Laboratory Calier, Spain) administered intramuscularly. The other protocols added butorphanol (0.1 mg/kg) (B) (Torbugesic 1 per cent; Fort Dodge Veterinaria, Spain) or morphine ((0.2 mg/kg) (M2) or (0.4 mg/kg) (M4)) (Morphine 2 per cent; Braun Medical, Spain) …