Comparison of rectal and vaginal temperature daily rhythm in dogs (Canis familiaris) under different photoperiod

Chronophysiology of domestic animals

This review highlights recent findings on biological rhythms and discusses their implications for the management and production of domestic animals. Biological rhythms provide temporal coordination between organs and tissues in order to anticipate environmental changes, orchestrating biochemical, physiological and behavioural processes as the right process may occur at the right time. This allows animals to adapt their internal physiological functions, such as sleep-wake cycles, body temperature, hormone secretion, food intake and regulation of physical performance to environmental stimuli that constantly change. The study and evaluation of biological rhythms of various physiological parameters allows the assessment of the welfare status of animals. Alteration of biological rhythms represents an imbalance of the state of homeostasis that can be found in different management conditions.

Short Communication: Use of Infrared Thermometers for Cutaneous Temperature Recording: Agreement with the Rectal Temperature in Felis catus

Simple Summary

The recording of body temperature by rectal temperature assessments is a stressful procedure for cats. For this purpose, alternative methods for using rectal digital thermometers to monitor body temperature were investigated. Skin temperature was recorded in 20 cats, in 5 different body regions, and compared with the rectal temperature. The obtained data indicated that the cutaneous temperature recorded by the infrared thermometers was not in agreement with the data recorded by the digital thermometer in the rectum.

Abstract

In veterinary medicine, the gold standard for assessing body temperature is rectal temperature assessment. Considering that this procedure is stressful for many species, in particular for cats, it could be clinically important to consider an alternative approach for the monitoring of core body temperature. The aim of this study was to test if cutaneous temperature measurements by means of different infrared thermometers are in agreement with the most commonly used method for body temperature measurement in cats. The cutaneous temperature was recorded in the jugular, shoulder, rib, flank, and inner thigh, using three different non-contact infrared thermometers (IR1, IR2, and IR3) in 20 cats. The cutaneous temperature was then compared to the rectal temperature, recorded by means of a digital thermometer. The obtained data indicated that the cutaneous temperature recorded by the infrared thermometers was not in agreement with the data recorded by the digital thermometer in the rectum. In cats, the use of non-contact infrared thermometers gave no reproducible or constant data to justify their application for the recording of body temperature instead of rectal temperature recording. In addition, the infrared temperature measurement devices generated results that were not in good agreement among themselves, providing a novel result of clinical importance.

Thermographic ocular temperature correlated with rectal temperature in cats

Body temperature reflects the animal health and/or disease conditions. During clinical examination, temperature measurement is a basic step in veterinary medicine. The conventional method used is the rectal thermometry, particularly stressful in some subjects, especially for cats. A less stressful alternative method, such as infrared thermal imaging camera, is used in various fields of medicine for diagnosis, prognosis and correct therapeutic approaches. To evaluate the usefulness of infrared thermal imaging for the assessment of ocular temperature, twenty cats of different breeds (European, Siamese and Persian, 4-6 years old, mean body weight 4.3 ± 0.30 Kg) were enrolled in the study. In order to evaluate the applicability of the ocular temperature assessment through thermal imaging as a tool for measuring the animal's body temperature, the obtained values were compared with the rectal temperature values recorded in each cat by means of a digital thermo-camera. There were no differences between left and right eye; and a difference of about 1.19 °C between the ocular and rectal temperature value was recorded (p < 0.0001). Rectal and ocular temperatures were positively correlated (p < 0.0001; r = 0.93). In conclusion, we show that ocular temperature is an alternative method for body temperature measurement that can be used in clinical evaluation of cats, especially in cases where rectal temperature recording is not possible.

Comparison between rectal and body surface temperature in dogs by the calibrated infrared thermometer

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Dogs poorly tolerate rectal temperature measurements with a contact thermometer.

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Existing alternative approaches used uncalibrated infrared thermometers.

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Gum and inguinal temperature are correlated moderately to rectal temperature.

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Hyperthermia was detected with sensitivity and specificity up to 90.0% and 78.6%.

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Future studies should include a calibrated thermometer and control external factors.

Because dogs tolerate conventional rectal temperature measurements poorly, a calibrated infrared thermometer was tested for assessing canine body surface temperature. Body surface temperature of 204 dogs was estimated on various sites (digit, snout, axilla, eye, gum, inguinal region, and anal verge). Having rectal temperature as the gold standard, temperature difference, Spearman's correlation coefficient, hyperthermia and hypothermia detection sensitivity and specificity, and stress response score was calculated for each measurement site. Although the canine body surface temperature was considerably lower than the rectal temperature, there was a moderate correlation between both temperatures. Spearman's coefficients were 0.60 (p < 0.001) for the inguinal region with a single operator and 0.50 (p < 0.001) for the gum with multiple operators. Measurement site on the gum additionally guaranteed hyperthermia detection sensitivity and specificity up to 90.0% (95% CI: [66.7 100]) and 78.6% (95% CI: [71.6 85.2]), respectively. Measurements with the infrared thermometer provoked a statistically significant lower stress response (mean stress scores between 1.89 and 2.48/5) compared to the contact rectal measurements (stress score of 3.06/5). To conclude, the correct body surface temperature measurement should include a calibrated thermometer, reliable sampling, and the control of external factors such as ambient temperature influence. The transformation of body surface temperature to the recognized rectal temperature interval allows more straightforward data interpretation. The gum temperature exhibited the best clinical potential since the differences to rectal temperatures were below 1°C, and hyperthermia was detected with the sensitivity of up to 90%.