A Comparison Between the Effects of Xylazine-Ketamine and Xylazine-Thiopental Combinations on Cardiac Rhythm in Dogs

Objective- To compare the effects of xylazine-ketamine and xylazine-thiopental on cardiac rhythm in dogs. Design- Experimental study. Animals- 15 mixed-bred, adult dogs of either sex. Procedures- Following premedication with xylazine HCI, either ketamine HCI or sodium thiopental were administered to dogs. Cardiac rhythm was evaluated before as well as 15,30,45, and 60 minutes and3 days after induction of anesthesia. Results- Sinus arrest block and first degree atrioventricular (A-V) block were the most common arrhythmias observed after ketamine administration. During thiopental-induced anesthesia, ventricular premature beats with bigeminy pattern and sinus bradycardia were also recorded. Conclusion and Clinical Relevance-Concerning the documented effects of the aforementioned drugs on cardiac rhythm, arrhythmias might be induced by the combination of xylazine with both anesthetic drugs.