Cis-atracurium neuromuscular blockade in dogs

This study was conducted to evaluate the onset, duration of action and potency of cis-atracurium in dogs. Ten apparently healthy dogs of various breeds were used in this study. The age and weight of the dogs were 3.2 ± 2.4 year and 17.7 ± 4.8 kg, respectively. All dogs pre-medicated with acepromazine 0.05 mg/kg and morphine 0.5 mg/kg. After induction of general anesthesia with thiopental, the dogs were intubated and anesthesia maintained with halothane in oxygen. After reaching good depth of anesthesia, cis-atracurium were injected intravenously at the dose of 0.1 mg/kg and neuromuscular blockade (NMB) evaluated by counting visual responses to train-of-four (TOF) nerve stimulation on ulnar nerve. All four responses eliminated in 9 out of 10 dogs. The onset was 4.8 ± 1.3 min and the duration of NMB lasted for 24.4 ± 9 min. The quality of relaxation was good according to surgeons. It is concluded that cis-atracurium is an effective neuromuscular blocking agent in the dog, although its potency varies slightly in different dogs.