Evaluation of infrared thermometry technique as an alternative to rectal technique in dogs in Kampala, Uganda

Abstract

Temperature measurement is a prime technique for assessing the health status of a patient, crucial in the diagnosis and consequently paramount in monitoring the management of febrile conditions. In human, several types of thermometers are available for estimation of body temperature under two thermometry techniques; infrared or rectal technique, sublingual, under the armpit. However, in animals, for routine clinical practice, only rectal thermometry is commonly used. This method possesses various challenges including stress, cross contamination, injury and time consuming, hence a need for a less invasive technique. This study aimed to evaluate the effectiveness of infrared thermometry technique (IRT) as an alternative body temperature estimation method to rectal technique in dogs in Kampala metropolitan. We also sought to ascertain whether certain animal factors affected the differences between the measurements. One hundred and forty-eight dogs of different breeds were sampled using the paired comparison approach targeting animals for routine visits to selected veterinary clinics and those resident in canine shelters. Predictive/equilibrium digital thermometer and mercury-in glass thermometers were used for rectal temperature measurement while an infrared thermometer (model: F102, accuracy ±0.20C, production date of 2020-03-29, production batch number of 20200329-1) was used for reading temperatures in ear, eye and perineal area remotely. All recordings were obtained by the same investigator in a randomized fashion. Age, breed, sex and body condition score on a scale of five were recorded for each of the selected dogs. Raw data was analyzed using STATA 14-2(Stata Corp USA, Texas). The median digital RT, ear, eye and perineal area temperature readings were 38.40C, 37.40C, 36.80C, 37.60C, with means (Sd) of 38.80C±0.75, 37.50C±0.94, 36.90C±0.62, 37.70C±0.96 respectively. The median age in months (IQR) of 12(5-36) and mean BCS (Sd) of 2.9±0.56. At the lower cutoff of 37.20C, IRT had a sensitivity of 100% and specificity of 70.1% but with a lower sensitivity at the higher cutoff (39.40C) of 21.1% and specificity of 96.1% Breed (German Shepherd, p=0.026) and age (p=0.003) had statistically significant influence on the IRT ear results. No effect of sex and body condition score was observed (p>0.05). IRT underperformed compared with the rectal method though IRT at the perineal area proved a reliable screening method for hypothermia using the linear regression equation but not as an alternative to rectal technique in clinical practice.