Measurement of body temperature by use of auricular thermometers versus rectal thermometers in dogs with otitis externa

OBJECTIVE: To compare measurements of body temperature obtained with auricular thermometers versus rectal thermometers in dogs with otitis externa. DESIGN: Prospective study. ANIMALS: 100 client-owned dogs: 50 with and 50 without clinical evidence of otitis externa. PROCEDURE: Dogs were evaluated for the presence of otitis externa on the basis of clinical signs, otoscopic examination, and cytologic evaluation of ear exudate. Auricular and rectal temperatures were obtained simultaneously in all dogs prior to and following ear examination. RESULTS: There was a high correlation between auricular and rectal temperatures in dogs with otitis externa both prior to and after ear manipulation. Significant differences were not detected in temperature measurements among dogs with different degrees of otitis externa. CONCLUSIONS AND CLINICAL RELEVANCE: Auricular temperature readings obtained by use of an auricular thermometer in dogs with otitis externa are accurate measurements of body temperature, compared with rectal temperature measurements. Temperature measurements are reliable before and after examination of the ear canal.     

A comparison of auricular, rectal and pulmonary artery thermometry in dogs with anesthesia-induced hypothermia

Objective: To determine if a correlation exists among auricular, rectal and pulmonary artery (PA) temperatures in hypothermic dogs. Design: Prospective study. Setting: Angiography suite at a college of veterinary medicine. Animals: Sexually intact female research hounds (13.9–25.4 kg; n=8). Measurements and main results: Dogs were anesthetized for instrumentation with a percutaneously placed, thermistor‐tipped, PA catheter. Anesthesia was maintained until the core body temperature decreased to 36.6°C (97.8°F). Anesthesia was discontinued, and auricular and rectal temperatures were obtained every 15 minutes until the PA temperature reached 38.3°C (100.9°F). A strong correlation was noted among the 3 methods of temperature measurement (P<0.001; R≥0.846). No statistical difference was detected among measurement methods at baseline, the minimum temperature attained, nor the median temperature attained. However, at the maximum temperature attained, auricular measurements (37.7±0.4°C or 99.8±0.7°F) were lower than either the rectal (38.3±0.3°C or 100.9±0.5°F) or PA (38.3±0.3°C or 100.9±0.5°F) temperature measurements (P=0.001). Conclusion: There is a strong correlation among rectal, auricular and PA temperatures. Auricular temperature may be used to monitor core body temperature during postoperative rewarming; however, it might be slightly lower than core temperature as normothermia is reached.     

Comparison between auricular and standard rectal thermometers for the measurement of body temperature in dogs

Although the rectal mucosa remains the traditional site for measuring body temperature in dogs, an increasing number of clinicians have been using auricular temperature to estimate core body temperature. In this study, 88 mature healthy dogs had body temperatures measured with auricular and rectal thermometers. The mean temperature and confidence intervals were similar for each method, but Bland-Altman plots showed high biases and limits of agreement unacceptable for clinical purposes. The results indicate that auricular and rectal temperatures should not be interpreted interchangeably.     

A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

Background

The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV). Subcutaneous tissue temperatures obtained by the implantable transponders were compared with rectal temperatures, recorded by a conventional digital thermometer.

Methods

In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal temperature. To test the stability of the monitoring system in a larger group of pigs, transponders were therefore inserted by the left ear base in a subsequent infection experiment with 30 pigs.

Results

Generally, the microchip transponders measured a subcutaneous tissue temperature, which was about 1°C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found.

Conclusions

Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs. In contrast, however, the tested system did not constitute a suitable tool to measure body temperatures of individual animals in the present pig infection experiment.     

Comparison of temperature readings from a percutaneous thermal sensing microchip with temperature readings from a digital rectal thermometer in equids

OBJECTIVE: To compare temperature readings from an implantable percutaneous thermal sensing microchip with temperature readings from a digital rectal thermometer, to identify factors that affect microchip readings, and to estimate the sensitivity and specificity of the microchip for fever detection. DESIGN: Prospective study. ANIMALS: 52 Welsh pony foals that were 6 to 10 months old and 30 Quarter Horses that were 2 years old. PROCEDURES: Data were collected in summer, winter, and fall in groups 1 (n = 23 ponies), 2 (29 ponies), and 3 (30 Quarter Horses), respectively. Temperature readings from a digital rectal thermometer and a percutaneous thermal sensing microchip as well as ambient temperature were recorded daily for 17, 23, and 19 days in groups 1 through 3, respectively. Effects of ambient temperature and rectal temperature on thermal sensor readings were estimated. Sensitivity and specificity of the thermal sensor for detection of fever (rectal temperature, >or= 38.9 degrees C [102 degrees F]) were estimated separately for data collection at ambient temperatures 15.6 degrees C. RESULTS: Mean ambient temperatures were 29.0 degrees C (84.2 degrees F), -2.7 degrees C (27.1 degrees F), and 10.4 degrees C (50.8 degrees F) for groups 1 through 3, respectively. Thermal sensor readings varied with ambient temperature and rectal temperature. Rectal temperatures ranged from 36.2 degrees to 41.7 degrees C (97.2 degrees to 107 degrees F), whereas thermal sensor temperature readings ranged from 23.9 degrees (75 degrees F) to 42.2 degrees C (75 degrees to 108 degrees F). Sensitivity for fever detection was 87.4%, 53.3%, and 58.3% in groups 1 to 3, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The thermal sensor appeared to have potential use for initial screening of body temperature in equids at ambient temperatures > 15.6 degrees C.     

红外线体温仪在生猪屠宰场体温筛检中的试用效果

为寻找一种简单、快捷的宰前体温检测方法,设置警示温度,随机抽取宰前猪1000头,分别用水银温度计测量肛温,用红外线体温仪和电子体温计测量耳根表面温度。结果显示,红外线体温仪的检测结果与水银温度计检测结果符合率为93.11%。因此,红外线体温仪比较适合用于较大规模屠宰场的宰前检疫体温初筛。     

Effects of ear type, sex, age, body weight, and climate on temperatures in the external acoustic meatus of dogs.

OBJECTIVE: To investigate effects of ear type, sex, age, body weight, and ambient climatic conditions on external acoustic meatus (external ear canal) temperatures in dogs. ANIMALS: 650 dogs without clinical signs of ear disease. PROCEDURE: Dogs were assigned to 5 groups on the basis of auricular conformation and amount of hair in the external ear canal and 4 groups on the basis of body weight or age. External ear canal temperatures (EECT) were measured, using an infrared thermometer. Mean EECT determined for each group were compared to evaluate effects of ear type, age, weight, and sex, and EECT measured at different ambient temperatures and humidities were compared to determine climatic effects. RESULTS: Dogs with hirsute ear canals had significantly lower EECT than dogs with hairless ear canals, whereas significant differences were not detected between dogs with erect and pendulous auricles. Dogs < 6 years old had higher EECT than older dogs, and dogs that weighed < 6 kg had lower EECT than larger dogs. External ear canal temperatures measured when ambient temperatures were < 25 C were less than those measured at warmer temperatures. Sex and relative humidity did not affect EECT CONCLUSIONS AND CLINICAL RELEVANCE: EECT of dogs without ear disease were affected by weight and age, amount of hair in the external ear canal, and ambient temperature. However, hirsute ears had lower, not higher, EECT than hairless ears, suggesting that EECT may play less of a role in the development of otitis externa than believed.     

The use of the hand-held infrared thermometer as an early detection tool for exertional heat illness in Thoroughbred racehorses: A study at racetracks in eastern Australia

Thoroughbred racehorses perform exercise at maximal intensities and typically display a hyperthermic exercise response, which can drive core body temperature to critical levels. Despite extremely efficient thermoregulatory mechanisms, certain weather conditions may affect the horse’s ability to cool and result in a syndrome referred to as exertional heat illness (EHI). This is characterised by central nervous system dysfunction, as well as cytotoxic effects of heat on cells, which can produce deleterious consequences. Early detection of exertional heat illness (EHI) in Thoroughbred racehorses can be difficult because signs are often vague and the measurement of rectal temperature as an indicator of hyperthermia is not practical. Best practice in the treatment of EHI in horses, as in human subjects, centres on early detection, rapid assessment and aggressive cooling. Research in human subjects has shown that EHI is manageable when recognised early and appropriate treatment provided. The aim of this study was to investigate the measurement of skin surface temperature (SST) by an infrared thermometer as an aid in the early detection of EHI. A skin surface temperature ≥39°C in the immediate postrace period is considered to be hot. It reflects the interaction of exercise-related metabolic heat production, physiological adjustments to the skin surface such as vasodilation and sweating, together with the effect of high ambient temperature. Most importantly, high SST is associated with a reduced core-to-skin temperature difference, which retards heat transfer from the deep body tissues to the skin and can hinder heat dissipation. Identification of horses with high SSTs can prioritise them for rapid cooling and curtail possible progression to EHI.     

Comparison of body temperature using digital,infrared, and tympanic thermometry in healthy ferrets (Mustela putorius furo)

BackgroundThe aim of this study was to evaluate the comparative precision and accuracy of multiple methods of thermometry used to assess body temperature in healthy adult ferrets.MethodsTemperature was measured in 20 healthy ferrets (Mustela putorius furo) using noncontact infrared thermometry, digital thermometry in the rectal, inguinal, and axillary regions, and infrared contact-based thermometer in the ear (tympanic) and on the skin of the dorsal back between the shoulder blades. Temperatures were taken pre- and posthandling, evaluated across the set of ferrets for general precision and effect of handling, and compared to assess accuracy. Intraclass correlation analysis and Bland-Altman agreement analyses with rectal temperature being used as reference were conducted.ResultsSample time (before and after physical examination) and day (day #1 and day #2), were found to not to be significantly different with respect to temperature measurements (P > 0.05). Reproducibility was not high for any of the temperature measurement methods, but was moderate for rectal and tympanic ear measures. The lowest mean difference with rectal temperature was found for tympanic thermometry on the dorsal skin when compared with rectal measurement (+0.05° C), as opposed to the other four methods of temperature measurement which ranged in their mean differences when compared with rectal measurement (−7.4 to −0.58° C). Agreement analyses showed constant error and proportional error only for the inguinal temperature method.Conclusions and clinical relevanceTemperature measurements due to tympanic thermometers applied on the dorsal skin have some agreement with respect to digital rectal thermometry in ferrets. Following further validating studies on hypothermic and hyperthermic contexts of usage, this less invasive approach may be a useful method for temperature measurement in clinical settings to reduce stress of the patient and increase efficiency without sacrificing accuracy.     

Usefulness of infrared thermometry in determining body temperature in mice

The rectal temperature obtained using a standard electronic thermometer was compared with ear, back skin, tail skin, and sole skin temperatures obtained using an infrared thermometer in B6C3F1 mice. Using both methods, we investigated baseline temperatures, diurnal and 2-week variations in temperatures, and ethanol-induced hypothermia in these body locations. Ear and back temperatures were shown to be close to and consistent with rectal temperatures in various situations, and measured temperatures at these sites were almost constant, with very similar diurnal variation. Conversely, tail and sole temperatures were lower and much more variable. These results indicate that ear and back skin temperatures obtained using a convenient and non-invasive infrared thermometer are as reliable, and should be safer and less stressful to animal subjects, compared to standard rectal temperature measurements.     

Comparison of axillary and inguinal body temperature to rectal temperature in healthy guinea pigs (Cavia porcellus)

Background: Core body temperature is a crucial health parameter. Temperature aberrations can indicate certain infectious or inflammatory disorders, influence clinical management decisions, and serve as a prognostic indicator for patient recovery. Historically, rectal temperature measurements have been utilized in small companion zoologic animals. However, there is a growing interest in less invasive methods including auricular and axillary measurements to determine core body temperature. Methods: Temperature measurements were obtained from three locations (axillary [AT], inguinal [IT], and rectal [RT]) in a randomized order and performed in duplicate in 40 healthy guinea pigs during a handling period spanning less than 3 minutes. Results: Obtaining RT was safely performed in all animals. IT (mean = 38.1°C) and AT (mean 38.5°C) were significantly lower than RT (mean = 38.8°C; P < 0.0001 and P = 0.0001, respectively). Constant and proportional error was observed between RT and IT, but not between AT and IT as well as AT and RT. Conclusions and clinical relevance: Based on the clinically significant differences in difference of the mean, wide limits of agreement and outlying data points on Bland-Atman analyses, RT should remain the clinical gold standard to measure core body temperature in guinea pigs. Obtaining RT in the guinea pig is safe and causes no overt harm and could add additional information to a veterinary assessment.     

Comparison of prothrombin time, activated partial thromboplastin time, and fibrinogen concentration in blood samples collected via an intravenous catheter versus direct venipuncture in dogs

OBJECTIVE: To compare prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen concentration in canine blood samples collected via an indwelling IV catheter and direct venipuncture. ANIMALS: 35 dogs admitted to an intensive care unit that required placement of an IV catheter for treatment. PROCEDURES: Blood samples were collected via IV catheter and direct venipuncture at the time of catheter placement and 24 hours after catheter placement. Prothrombin time, APTT, and fibrinogen concentration were measured. RESULTS: 5 dogs were excluded from the study; results were obtained for the remaining 30 dogs. Agreement (bias) for PT was -0.327 seconds (limits of agreement, -1.350 to 0.696 seconds) and 0.003 seconds (limits of agreement, -1.120 to 1.127 seconds) for the 0- and 24-hour time points, respectively. Agreement for APTT was -0.423 seconds (limits of agreement, -3.123 to 2.276 seconds) and 0.677 seconds (limits of agreement, -3.854 to 5.207 seconds) for the 0- and 24-hour time points, respectively. Agreement for fibrinogen concentration was -2.333 mg/dL (limits of agreement, -80.639 to 75.973 mg/dL) and -1.767 mg/dL (limits of agreement, -50.056 to 46.523 mg/dL) for the 0- and 24-hour time points, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Agreement between the 2 techniques for sample collection was clinically acceptable for PT, APTT, and fibrinogen concentration at time 0 and 24 hours. It is often difficult or undesirable to perform multiple direct venipunctures in critically ill patients. Use of samples collected via an IV catheter to monitor PT and APTT can eliminate additional venous trauma and patient discomfort and reduce the volume of blood collected from these compromised patients.     

Assessment of the use of temperature-sensitive microchips to determine core body temperature in goats

Body temperature was measured at five different body sites (retroperitoneum, groin, semimembranosus muscle, flank and shoulder) using temperature-sensitive microchips implanted in five female goats, and compared with the core body and rectal temperatures. Body temperature was measured while the goats were kept in different ambient temperatures, with and without radiant heat, as well as during a fever induced experimentally by injection of bacterial lipopolysaccharide. Bland-Altman limit of agreement analysis was used to compare the temperature measurements at the different body sites during the different interventions. Temperatures measured by the microchip implanted in the retroperitoneum showed the closest agreement (mean 0.2 °C lower) with core and rectal temperatures during all interventions, whereas temperatures measured by the microchips implanted in the groin, muscle, flank and shoulder differed from core body temperature by up to 3.5 °C during the various interventions.     

Comparison between core temperatures measured telemetrically using the CorTemp? ingestible temperature sensor and rectal temperature in healthy Labrador retrievers

This study evaluated the CorTemp^® ingestible telemetric core body temperature sensor in dogs, to establish the relationship between rectal temperature and telemetrically measured core body temperature at rest and during exercise, and to examine the effect of sensor location in the gastrointestinal (GI) tract on measured core temperature. CorTemp^® sensors were administered orally to fasted Labrador retriever dogs and radiographs were taken to document sensor location. Core and rectal temperatures were monitored throughout the day in 6 resting dogs and during a 10-minute strenuous retrieving exercise in 6 dogs. Time required for the sensor to leave the stomach (120 to 610 min) was variable. Measured core temperature was consistently higher than rectal temperature across all GI locations but temperature differences based on GI location were not significant (P = 0.5218). Resting dogs had a core temperature that was on average 0.4°C above their rectal temperature with 95% limits of agreement (LoA) between 1.2°C and −0.5°C. Core temperature in exercising dogs was on average 0.3°C higher than their concurrent rectal temperature, with LoA of +1.6°C and −1.1°C.     

A Comparative Study of Non-contact Infrared and Digital Rectal Thermometer Measurements of Body Temperature in the Horse

Equine body temperature taken with a non-contact infrared thermometer (NCIT) does not correlate well with the equine body temperature taken with a digital rectal thermometer (DRT), when it comes to absolute temperatures. There is significant variation in body temperature readings depending on the site at which the temperature was taken. NCIT may still may have, in that it does seem to be able to reliably detect when temperatures are more than that which is clinically normal, and does not seem to give falselyelevated readings in clinically normal horses. In horses that resent having their temperatures taken rectally, the NCIT seems to offer the equine clinician a quick and easy way to at least determine whether the horse's temperature is at or more than normal, even if it does not agree with DRT results.     

Telemetric measurement of body core temperature in exercising unconditioned Labrador retrievers

This project evaluated the use of an ingestible temperature sensor to measure body core temperature (Tc) in exercising dogs. Twenty-five healthy, unconditioned Labrador retrievers participated in an outdoor 3.5-km run, completed in 20 min on a level, 400-m grass track. Core temperature was measured continuously with a telemetric monitoring system before, during, and after the run. Data were successfully collected with no missing data points during the exercise. Core temperature elevated in the dogs from 38.7 ± 0.3°C at pre-exercise to 40.4 ± 0.6°C post-exercise. While rectal temperatures are still the standard of measurement, telemetric core temperature monitors may offer an easier and more comfortable means of sampling core temperature with minimal human and mechanical interference with the exercising dog.     

Percutaneous endoscopic tube gastrostomy in dogs

Percutaneous endoscopic tube gastrostomy was performed in 10 dogs, using mushroom-tip catheters (16 to 24 F) maintained in place for 5 to 32 days. Dogs were observed daily. Although placement of the catheter was simple and quick, 3 dogs destroyed their catheters. Patency of the catheter was maintained with or without regular flushings with saline solution. Pyrexia (greater than or equal to 39.4 C) developed in 3 dogs, but the rectal temperature returned to base line within 24 hours after catheter removal. After catheter removal, all wounds healed without complication. All dogs were euthanatized. Five were examined radiographically before euthanasia to determine the fate of the mushroom tip after transection of the catheter at skin level between days 5 and 21, and 5 dogs were evaluated at postmortem examination between days 10 and 32. In all dogs, the tip was not present in the gastrointestinal tract by 96 hours after catheter transection. During postmortem examination of the 5 dogs, minimal inflammatory lesions were seen in the gastric tissue. A gastrocutaneous fistula had formed in each dog, resulting in an adhesion between the stomach and peritoneum.     

Evaluation of four warming procedures to minimise heat loss induced by anaesthesia and surgery in dogs

OBJECTIVE: To evaluate the efficiency of four warming procedures, introduced after anaesthetic induction and continued during surgery, in minimising heat loss in anaesthetised dogs. DESIGN: Dogs were paired. One of each pair was a control; the other was subjected to one of four warming procedures. METHODS: Ninety-six dogs were involved in total. Pairs of dogs were matched for breed, hair length, and type of surgical procedure and placed adjacent to each other in a large temperature-controlled surgical theatre. One dog within each pair was assigned to one of four warming procedures that commenced immediately after anaesthetic induction. Group 1 (11 pairs) were placed on a purpose-designed prewarmed (41 degrees C) electrically heated pad. Group 2 (18 pairs) were placed on a prewarmed electric heat pad (41 degrees C), cocooned by four wrapped water bottles (initially 41 degrees C) and subjected to radiant heat (150 watt lamp placed 50 cm away from the head of the dog). Group 3 (11 pairs) were surrounded by a forced air warming mattress (set at 43 degrees C). Group 4 (8 pairs) were connected via the anaesthetic breathing circuit to a heater/humidifier (set at 41 degrees C). Rectal temperature measurements were recorded every 15 min for the first 3 h of anaesthesia. The fall in rectal temperature of the control dog was subtracted from the fall in temperature of the treatment dog and this measurement was used to assess the efficacy of the various warming procedures. RESULTS: The mean rectal temperature of unheated 'control' dogs decreased 1.9 +/- 0.6, 1.4 +/- 0.4 and 1.1 +/- 0.4 degrees C over the first, second and third hour respectively. After 3 h the temperature fall differential for all groups were 0.7 +/- 0.7 (Group 1), 3.1 +/- 1.1 (Group 2), 2.4 +/- 1.1 (Group 3) and 1.0 +/- 1.1 degrees C (Group 4). Thus the group 2 procedure was the most successful in preventing a drop of temperature followed by groups 3, 4 and 1. CONCLUSION: Large dogs undergo significant reduction in core body temperature especially during the first 2 h of anaesthesia and surgery. Supplementary warming substantially reduces this fall in body temperature, although certain warming procedures were found to be more effective than others.     

The accuracy of tactile assessment of canine nose temperature to identify rectal hyperthermia and hypothermia in dogs presenting on an emergency basis

The goals of this study were to evaluate whether touch can identify a warm nose as opposed to a cold nose, to examine the correlation between thermographically measured nose temperatures and rectal temperatures, and to calculate the accuracy of tactile assessment of nose temperature in detecting rectal hyperthermia and hypothermia in dogs. A total of 100 dogs presenting to an emergency room was prospectively enrolled. Tactile nose assessment was carried out on triage. Noses were subjectively categorized as warm, cold, or intermediate (neither warm nor cold). Thermographic nose temperatures were recorded using a thermal imaging camera. Tactile assessment categorized noses as warm, intermediate, or cold (P < 0.01). There was no correlation between thermographically measured nose temperature and rectal temperature (r = 0.02). Tactile assessment of noses as warm had a sensitivity of 29.4% and a specificity of 79.5% for detecting rectal hyperthermia; calculated test accuracy was 71%. Tactile assessment of noses as cold had a sensitivity of 54.5% and a specificity of 62.9%; calculated test accuracy was 62%. It was concluded that nose temperatures do not correlate with rectal temperatures. Tactile assessment of nose temperature is inaccurate for identifying rectal hyperthermia or hypothermia.     

Daily rhythmicity of body temperature in the dog

Research over the past 50 years has demonstrated the existence of circadian or daily rhythmicity in the body core temperature of a large number of mammalian species. However, previous studies have failed to identify daily rhythmicity of body temperature in dogs. We report here the successful recording of daily rhythms of rectal temperature in female Beagle dogs. The low robustness of the rhythms (41% of maximal robustness) and the small range of excursion (0.5 degrees C) are probably responsible for previous failures in detecting rhythmicity in dogs.