Hyperglycemia and hypoinsulinemia during xylazine-ketamine anesthesia in Thoroughbred horses.

This research investigated the effects of anesthesia, specifically using xylazine and ketamine, on blood glucose levels and insulin concentrations in Thoroughbred horses. It revealed that these drugs tend to elevate blood sugar and reduce insulin levels, with peak and lowest values often occurring shortly after administration.

Study Methodology

• The study involved 6 adult Thoroughbred horses. The chosen animals had doses of xylazine hydrochloride and ketamine hydrochloride administered intravenously.
• Xylazine hydrochloride was administered at a dose of 1.1 mg/kg and ketamine hydrochloride at 2.2 mg/kg. This dosage was sufficient to induce short periods of recumbency (lying down) and anesthesia.
• Blood samples were collected from the horses before, during, and after the anesthetic period to measure plasma glucose and serum insulin concentrations.

Study Findings

• Between 15 to 150 minutes after xylazine administration, a significant increase in plasma glucose (blood sugar) was observed. This increase peaked at 30 minutes after administration.
• Conversely, serum insulin concentrations significantly decreased from 5 to 90 minutes after the administration of xylazine, with the lowest point occurring at 15 minutes. Insulin, a hormone responsible for regulating blood glucose levels, was thus found to drop.
• Both these alterations in plasma glucose and serum insulin concentrations in xylazine-ketamine-anesthetized horses were seen to align with changes observed in horses sedated with xylazine alone. This implies the observed phenomena may be primarily attributable to xylazine rather than ketamine.

Significance of the Study

• This research provides insight into the metabolic changes induced by the use of xylazine and ketamine in horses, particularly focused on glucose metabolism.
• The results could help veterinarians understand the potential side-effects of these drugs and plan appropriate post-anesthesia care to manage any fluctuations in blood glucose and insulin levels.
• The study also adds to the body of knowledge on how anesthesia impacts the broader physiological processes in horses, which could inform future veterinary procedures and drug development.