AN ASSESSMENT OF EPIDURAL KETAMINE FOR HINDLIMB ANESTHESIA IN DOGS

Abstract

The effect of epidural ketamine was studied in 20 experimental dogs premedicated with 0.04 mg/kg atropine and 2 mg/kg xylazine, given intramuscularly along with 0.2 mg/kg acepromazine given intravenously. All dogs received, epidurally, 2 mg/kg ketamine diluted in 0.9% normal saline (NSS) in a volume of 1 ml/ 4.5 kg and, one week or more before, or later, 1 ml/ 4.5 kg NSS without ketamine as a control. Animal response to pain
stimulation was evaluated before, and during a surgical approach on the medial aspect of the tibia. The respiratory rates, heart rates and arterial blood pressures were measured before and after premedication and at 15, 30, 45, 60, 75, 90, 105 and 120 min after epidural administration of ketamine and NSS. The tibia could be surgically approached in all 20 dogs after receiving ketamine epidurally while the operation could not be done in 19 of them after receiving epidural NSS. However, the surgical approach could be done in those dogs after giving local lidocaine or intravenous thiopental. The respiratory rates, heart rates and arterial blood pressures after epidural ketamine were not significantly different (p>0.05) from those after epidural NSS, when used in conjunction with local
lidocaine or intravenous thiopental. According to this study epidural ketamine has been shown to have an analgesic effect enabling hindlimb surgery with no adverse effects on respiration and circulation in dogs.