Khosro Safari-Nikoo - Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran.
Abbas Raisi - Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran.
Amir Zakian - Department of Clinical Sciences, Faculty of Veterinary Medicine, Lorestan University, Khorramabad, Iran.
Ahmad Reza Mohamadnia - Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran.

Objective- This practice performed to compare the quality of analgesia, hematological parameters, and prevalence of cardiac dysrhythmias following epidural administration of lidocaine, lidocaine-meloxicam, and lidocaine-Metamizole sodium in cows.Animals- Fifteen adult Holstein cows aged between ۳-۵ years were assigned into three equal groups. Design- Each cow received the lidocaine (۰.۲۲ mg/kg), lidocaine-meloxicam (۰.۱۱ mg/kg – ۰.۲۵ mg/kg) or lidocaine-Metamizole sodium (۰.۱۱ mg/kg -۴ mg/kg) randomly via epidural injection into first intercoccygeal space. Procedure- Analgesia onset and duration were recorded. Heart rate, respiratory rate, rectal temperature, and ruminal motility were also recorded at ۰, ۵, ۱۵, ۳۰, ۴۵, ۶۰, ۹۰ and ۱۲۰ minutes, Electrocardiograms at ۰, ۶۰ and ۱۲۰ minutes and blood samples were collected through the caudal vein at ۰, ۳۰, ۶۰, ۹۰ and ۱۲۰ minutes. Detection of arrhythmias was done by checking ۶۰ seconds of each electrocardiogram.Results- analgesia onset in lidocaine-metamizole treatment was significantly longer than that of the other groups (p ۰.۰۵). Also, the duration of analgesia was significantly longer in lidocaine treatment compared to other experimental groups (p <۰.۰۵). There were no significant differences among heart rate, respiratory rate, rectal temperature, and ruminal motility between experimental groups (p >۰.۰۵). Hematological parameters changes were not significantly different and all of the detected cardiac arrhythmias were physiologic among treatments (p > ۰.۰۵).Conclusions and Clinical Relevance- Aforementioned dosages could be used in cows without any clinical, cardiac, and hematological side effects. Lidocaine analgesia was reliable; however, the authors were not sure about adequate analgesia resulted after injection the half-dose of meloxicam and Metamizole in combination with lidocaine therefore, further studies should be done.

Epidural Analgesia, Electrocardiography, Lidocaine, Meloxicam/Metamizole, Cow