EVALUATION OF THE ACCURACY OF DIFFERENT METHODS OF MONITORING BODY TEMPERATURE IN ANESTHETIZED BROWN BEARS (URSUS ARCTOS)

Abstract

There is some evidence that the handheld rectal thermometer does not accurately measure core temperature in bears. The objective of this study was to compare body temperature measured by the handheld digital thermometer (HDT), deep rectally inserted core temperature capsules (CTCs), and gastrically inserted CTCs in anesthetized brown bears (Ursus arctos). Twenty-two brown bears were immobilized with a combination of zolazepam-tiletamine and xylazine or medetomidine. After immobilization, one CTC was inserted 15 cm deep into the animal's rectum (DRTC) with a standard applicator, and another CTC was inserted into the stomach (GTC) via a gastric tube inserted orally. Temperature was measured every 5-10 min with an HDT. Paired temperature data points were analyzed with the Bland-Altman technique for repeated measurements and regression analysis with a significance level of 0.05. The mean difference ± SD of the difference between HDT and GTC readings was 0.27 ± 0.47 degrees C and the 95% limits of agreement (LoA) were 1.20 and -0.66 degrees C. The determination coefficient (r2) found between these methods was 0.68 (P < 0.0001). The mean difference ± SD of the difference between HDT and DRTC readings was 0.36 ± 0.32 degreesC and the 95% LoA were 1.0 and -0.28 degrees C. The r2 between HDT and DRTC was 0.83 (P < 0.0001). The mean difference ± SD of the difference between the two insertions of the VitalSense capsules was -0.06 ± 0.24 degrees C and the 95% LoA were 0.42 and -0.54 degrees C. The r2 found between GTC and DRTC was 0.91 (P < 0.0001). This study demonstrates that DRTC provided accurate measurement of core temperature and that HDT did not accurately measure core temperature, compared with GTC in anesthetized brown bears.

Challenges of measuring body temperatures of free-ranging birds and mammals

“…The temperature of any anatomical region is a product of metabolic heat production and blood flow within that region, including the rate of heat lost from physical processes [10]. Confusingly rectal or cloacal temperature is often used synonymously with the terms core or deep body temperature and not surprisingly considerable research effort has been invested in cross-validation of techniques to measure these respective temperatures [11][12][13][14]. Therefore, for any study involving body temperature measurement it is important to understand the spatial variation and differential regulation in temperature within the body and how the temperature of different body regions may change with time and environmental context.…”

The impact of clamp castration on the behaviour and body temperature of reindeer (Rangifer tarandus tarandus) – Effects of local anesthesia and non-steroidal anti-inflammatory drug.

“…Heat stress in reindeer is highly related to capture method, with additive effects from physiological and mental stressors, such as fear, metabolic heat from muscular exertion, anaesthetic drugs, or high ambient temperature (Lian et al, 2018). The normal body temperature for resting reindeer is 38.6 ± 0.2ºC (Blix et al, 2011), and rectal temperature may be even lower than the core body temperature (Ozeki et al, 2014). Signs of heat stress begin at a brain temperature of 39.0 ºC whereas the threshold for selective brain cooling during exercise is elevated to 39.5ºC (Blix et al, 2011).…”

Studies on Physiological and Hemato-Biochemical Changes during Xylazine-Zolazepam + Tiletamine and Dexmedetomidine - Zolazepam + Tiletamine Anesthesia in Sloth Bears

“…No significant changes were observed in biochemical values. temperature -0 F; Respiratory ratebreath/minute; Heart rate-beats/ minute) were recorded using OT patient Monitor as suggested by Ozeki et al, (2014) (Fowler, 1978).…”