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

Comparison of Aural and Rectal Temperature in Dogs Presenting to an Emergency Room

Purpose

To compare rectal and aural temperatures in canines presenting to a small animal emergency room.

Patients and Methods

We performed a prospective cohort study conducted between June 2022 and October 2022. One hundred and fifty-two dogs were evaluated that were presented to a private practice emergency room. Temperatures were obtained on presentation using both an aural Braun ExacTemp and a rectal Vet-Temp Rapid Digital Thermometer. The order of temperature measurement was randomized and recorded. Dogs were classified into three groups based on recorded temperature; normothermic (n = 105), hypothermic (n = 24), and hyperthermic (n = 23). Additional recorded parameters included: patient signalment, heart rate, respiratory rate, presence or absence of aural debris, coat length (classified as short, medium or long), body weight, body condition score, pain score, as well as venous lactate and non-invasive blood pressure, if performed.

Results

The overall aural temperatures were significantly lower than rectal temperatures. The average rectal and aural temperatures were 38.7°C (range 36.6-40.7°C) and 38.3°C (range 35.7°C-40.4°C), respectively. Among all canines, there was a moderate, statistically significant relationship between rectal and aural temperatures (r = 0.636; p < 0.001) and this relationship remained significant with a weaker relationship for normothermic dogs (r = 0.411; p < 0.001). For hyperthermic and hypothermic dogs, there was not a statistically significant relationship between rectal and aural temperatures. Hyperthermic dogs had a significantly higher respiratory rate than other groups and hypothermic dogs were more likely to have a short haircoat. Lastly, ambient temperature, but not humidity, influenced patient temperature.

Conclusion

Our study found aural temperatures were consistently lower than rectal temperatures in dogs with both normal and abnormal rectal temperatures. Aural thermometry may not be an acceptable method of temperature measurement in the emergency patient cohort.

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.