Effects of the combination romifidine/tramadol drug administration on several physiological and behavioral variables in calves

Introduction-In calves, for human consumption, the use of drugs is limited by residue consideration. Furthermore minor surgical procedures and laparotomy are often performed in standing sedated cattle. For this sedation, opioids are often used with α2 agonists; they act in a synergic way to lower drug doses in order to reduce side effects. Aim-Effectiveness and safety of romifidine with tramadol compared with romifidine alone was evaluated for analgesia in calves. Materials and methods-Forty Brown Swiss, aged 2-6 months (range) were enrolled in the study. Romifidine alone (R Group) and with tramadol (RT Group) was administered. Heart rate (HR), respiratory rate (RR), systolic, diastolic and median arterial pressures (SAP, DAP, MAP), rectal temperature, degree of sedation and response to electrical stimulation of the coronary band (RS) were measured before and up to 60 minutes following drugs administration. Results-HR and RR are significantly decreased in both groups. Head height above ground (HHAG) is significantly decreased in both groups and it is significantly lower in R Group in all time points. Ataxia is significantly increased in both groups and it is lower in RT Group than R Group. RS is significantly decreased in both groups and it is lower in RT Group. Physiological data and HHAG were compared by using two way analysis of variance (ANOVA) for repeated measures followed by Bonferroni test, AS and RS were compared by using Friedman test. Discussion-The results obtained in this study demonstrate that calves of RT Group remain in quadrupedal position and do not feel pain, whereas calves of R Group reach recumbency maintaining it throughout the duration of monitoring. Conclusions-Romifidine with tramadol provides an effective sedative/analgesic effect and minor ataxia than romifidine alone. The protocol may be useful for minor surgical procedures in the standing calves.