Comparison of axillary and rectal temperatures for healthy Beagles in a temperature- and humidity-controlled environment

Calculation of a Reference Interval for Rectal Temperature in Adult Dogs Presenting for Veterinary Care Using an Algorithm for Mixed Data

Veterinarians rely on the measurement of canine body temperature to define the health status of dogs, but no studies exist defining a reference range for rectal temperature on a large group of dogs. The aim of this study was to define the rectal body temperature of dogs based on a large data set of diseased and healthy animals and to evaluate the capability of the employed algorithm to calculate reference intervals of numerical clinical data. Out of 24,013 recorded measurements, statistical analysis was applied to data from 9782 adult dogs that underwent clinical examination at a university clinic between 2008 and 2017. The reference interval was calculated using an algorithm developed by the Deutsche Gesellschaft für Klinische Chemie und Laboratoriumsmedizin e.V. as part of its Reference Limit Estimator software (version 1.40.36.07). The following values were excluded: multiple measurements in a given dog, samples without assigned age or dogs younger than one year, and values <30.0 °C and >43.0 °C. Out of 9782 adult dogs, 665 temperature measurements were identified as outliers, and 9117 were used for further statistical analysis. The mean rectal temperature was 38.6 °C (90% CI: 38.6-38.6 °C) with a reference interval of 37.7 °C (90% CI: 37.7-37.7 °C) to 39.5 °C (90% CI: 39.5-39.5 °C). Validation according to CLSI guidelines showed the results to be valid. The determination of a reference interval for rectal temperatures in dogs using an algorithm for mixed datasets yielded results comparable to the existing reference intervals. This demonstrates that the calculation of reference intervals from mixed datasets of clinical numerical data can be used to confirm existing reference intervals or establish such de novo.

Comparison of Axillary versus Rectal Temperature Timing in Canine and Feline Patients

Research on alternatives to rectal thermometry in canine and feline patients has focused on equipment and measurement location but not procedure duration. In a crossover clinical scenario, we evaluated the time prior to (Pre-TempT) and after (Post-TempT) rectal and axillary thermometry in a diverse demographic of canine (n = 114) and feline (n = 72) patients. Equipment duration was controlled to determine a presumptive total time (TTime) associated with each thermometry method. Pre-TempT and TTime were significantly shorter in axillary thermometry trials for both canine and feline pets (p < 0.001). There was no difference in Post-TempT between thermometry methods in canine patients (p = 0.887); however, the Post-TempT was longer in felines after axillary thermometry (p = 0.004). Reductions in Pre-TempT and TTime were not significant in Scottish Fold breed cats. Within the feline rectal trials, the TTime of domestic-long-haired breeds was significantly longer than that of domestic-short-haired breeds (p = 0.019). No other tested parameter (i.e., size, body shape, age, weight, breed, coat type, or procedure order) played a significant role in these results. Axillary thermometry was faster than rectal thermometry in both canine and feline pets, primarily due to the time associated with animal approach and restraint (Pre-TempT). These results have implications for optimizing clinic workflow, appointment durations, and patient handling time.

Comparison of axillary and inguinal temperature with rectal temperature in dogs at a veterinary teaching hospital

OBJECTIVES

The objective of the study was to determine the agreement between rectal, axillary and inguinal temperatures and to estimate the accuracy of these measurements in detecting hyperthermia and hypothermia in dogs presented at a veterinary teaching hospital in the tropical Guinea Savannah zone.

MATERIALS AND METHODS

Prospectively, body temperature was measured in 610 dogs, using digital thermometry in the axillary, inguinal and rectal regions.

RESULTS

Overall, axillary and inguinal temperatures significantly underestimated rectal temperature, with a mean difference of -0.39 ± 0.02°C (95% confidence interval: -0.43 to -0.35; limit of agreement: -1.27 to 0.49) and - 0.34 ± 0.02°C (95% confidence interval, -0.37 to -0.30; limit of agreement: -1.15 to 0.47), respectively. The limits of agreement of axillary and inguinal temperatures were wide and above the pre-determined maximal acceptable difference of ±0.50°C recommended for clinical significance of rectal temperature in dogs. Bland-Altman plots showed that the confidence intervals of the mean differences of axillary and inguinal temperatures did not include the value zero, thereby indicating that the tested methods lack agreement with rectal temperature. Sensitivity and specificity for the detection of hyperthermia with axillary temperature were 72.1% and 30.5%, respectively. In contrast, sensitivity and specificity for the detection of hyperthermia with inguinal temperature were 77.9% and 26.2%, respectively. The magnitude of disagreement between axillary, inguinal and rectal temperatures was affected by age, breed and sex being slightly lower in mature, non-native breed and female dogs.

CLINICAL SIGNIFICANCE

Axillary and inguinal temperature measurements in dogs significantly underestimated rectal temperature measurements by -0.39 ± 0.02°C and -0.34 ± 0.02°C, respectively. The results indicate that axillary and inguinal temperatures should not be used as a replacement for rectal temperature due to the wide limits of agreement. In addition, axillary and inguinal temperatures may not be suitable in detecting hyperthermia because the sensitivity were lower than the required set-point of 90.0% for clinical identification of hyperthermia.

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%.

Comparing alternatives to canine rectal thermometry at the axillary, auricular and ocular locations

Body temperature is an important component in the diagnosis and treatment of disease in canines. The rectal temperature remains the standard of obtaining temperature within the clinical setting, but there are many drawbacks with this method, including time, access, animal stress, and safety concerns. Interest in using infrared thermometry in canines to obtain body temperature has grown as animal scientists and veterinarians search for non-invasive and non-contact methods and locations of obtaining canine temperatures. Here, we review evidence on axillary, auricular, and ocular region canine thermometry and the degree to which measurements in these locations are representative of rectal temperature values. Instrumentation refinement and development, as well as morphologic differences, play an important role in the potential correlation between the rectal temperature and these other locations. These caveats have yet to be fully addressed in the literature, limiting the options for those seeking alternatives to rectal thermometry.