Comparison of required induction dose, induction and recovery characteristics, and cardiorespiratory effects of co-administration of ketofol with diazepam and midazolam in healthy dogs

Background: Co-administration of anesthetics has been employed to decrease potential unpleasant effects associated with single drug. OBJECTIVES: This study was designed to evaluate the effects of co-administration of ketofol with diazepam or midazolam in healthy dogs. METHODS: Six adult mix-breed male dogs were used. After sedation with acepromazine (0.1 mg/kg), anesthesia was induced with keteofol (KF; 1 ml contained 5 mg ketamine and 5 mg propofol), ketofol-diazepam (KFD), or ketofol-midazolam (KFM) (1 ml contained 5 mg KF and 2.5 mg diazepam or midazolam) randomly. All the dogs received the three treatments with at least one week interval. RESULTS: The total dose of ketofol used for induction of anesthesia in KF (4.2±0.44 mg/kg) was significantly higher than KFD (2.27±0.6 mg/kg) and KFM (1.68±0.25 mg/kg). The total dose of diazepam and midazolam used in KFD and KFM was 1.00±0.25 and 0.73±0.10 mg/kg, respectively (p>0.05). The time needed for sternal recumbency, standing position and normal walking was longer in KFD and KFM compared to KF (p<0.05). Heart rate (HR) showed significant increase in KF at several time points (p<0.05). Respiratory rate (fr) in KF showed a significant decrease during the anesthesia period compared to the base (p<0.05). HR and fr were more stable in KFD and KFM. Induction and recovery quality in the three treatments were acceptable. CONCLUSIONS: Co-administration of ketofol with diazepam and midazolam reduced the required induction dose and prolonged recovery in dogs. Diazepam and midazolam could attenuate the unfavorable effects of ketofol in some cardiorespiratory variables.