Abstract
The objectives of the present study were to: 1) compare body temperature of anesthetized brown bears obtained by Vital Sense® capsules (VS) inserted gastrically to those obtained by deep rectal VS and handheld digital thermometer (HDT) and 2) to evaluate the decrease in core body temperature produced by an active cooling protocol and by alpha-2 antagonism. Thirty-one brown bears were captured with a combination of zolazepam-tiletamine and xylazine or medetomidine. One VS capsule was inserted deep into the animals’ rectum and another into the stomach. Rectal temperature was also measured with the HDT and paired data points were analyzed with the Bland-Altman technique and regression analysis. In bears that demonstrated gastric temperatures ≥ 40oC a described active cooling protocol was performed and the temperature change was analyzed for 30 minutes. To determine if antagonism of the alpha-2 agonist decreased core body temperature in bears, change in temperature was analyzed for 30 minutes after the administration of IM atipamezole. A third group of bears were not cooled and temperatures were recorded for 30 minutes before administration of atipamezole. To compare the differences among the three groups an area under the curve was calculated for each individual bear and analyzed one-way analysis of variance with Tukey’s PostHoc test. To evaluate the change over time within each treatment a General Linea Model for repeated measures was performed, with Tukey’s PostHoc test. The significance level of all analyses was 5%. VS capsules accurately measured core temperature and HDT did not accurately estimate core temperature in anesthetized brown bears. The active cooling protocol used significantly decreased body temperature of hyperthermic bears after 10 minutes. Alpha-2 antagonist produced an earlier significant decrease but the final change in temperature (at Time 30) was lower than with active cooling. No significant difference was found between the two treatments.
