Perioperative blood glucose concentrations in kittens following overnight fasting and gonadectomy

Abstract

Objectives The objective of this study was to determine if hypoglycemia is an effect of overnight fasting and gonadectomy in kittens, as well as to determine predictors of baseline and postoperative blood glucose. Methods This was a prospective observational study. Seventy-five kittens between the age of 8 and 16 weeks undergoing routine castration or ovariohysterectomy at an animal shelter were included. Two blood glucose measurements were analyzed per kitten after an overnight fast: a baseline reading prior to preoperative examination, and a reading immediately postoperatively. Predictors of the baseline and postoperative blood glucose levels were determined using multi-level mixed-effects linear regression. Results Kittens, when fasted overnight, were not hypoglycemic (<60 mg/dl). No kittens exhibited clinical signs consistent with hypoglycemia. No kittens had a blood glucose <70 mg/dl postoperatively. Postoperative hyperglycemia (>150 mg/dl) was observed in 44% of kittens. The only predictor of fasted blood glucose levels was body condition score. The only predictor of postoperative blood glucose levels was the fasting blood glucose value. Conclusions and relevance Overnight fasting prior to elective sterilization in 8- to 16-week-old kittens did not result in hypoglycemia. Concern regarding hypoglycemia after a prolonged fast in kittens may be unwarranted for short procedures in healthy animals.

Figure 1

Baseline blood glucose values after overnight fasting. Lines at limit for hypoglycemia (60 mg/dl) and hyperglycemia (150 mg/dl)

Figure 2

Postoperative blood glucose values. Lines at limit for hypoglycemia (60 mg/dl) and hyperglycemia (150 mg/dl)

Figure 3

Box plot showing baseline (BG1) and postoperative (BG2) blood glucose values for kittens with BCS 4 and 5. Black line at median value

Figure 4

Paired plot showing postoperative blood glucose value (triangle BG2) ordered by baseline blood glucose value (circle BG1)