Ocular and Superficial Body Thermographic Findings in Sled Dogs before and after Competition

Abstract

Competitions involving sled dogs are rapidly growing and body temperature assessment could represent a prompt and non-invasive method of screening for potential pathological conditions during or after activity. The aim of this clinical study was to evaluate if thermography is able to monitor the pre- and post-competition ocular and superficial body temperature variations during a sled dog competition. It subsequently compared the data relating to the ocular temperatures in different race types: mid-distance (30 km) and sprint (≤16 km). Results showed a statistically significant increase in post-competition ocular temperature of both eyes, regardless of the length of the race. The relative increase in the temperatures of the other body surfaces was lower than the expected values, probably due to the influence of environmental and subjective factors such as the type of coat of the Siberian Husky or subcutaneous fat. Infrared thermography has therefore proved to be useful method in sled dog competition conditions for screening superficial temperature variations, as the investigation is normally conducted in an external environment and often in demanding work conditions.

Keywords: Siberian Husky; dog; sled; sled-dog; thermography.

Figure 1

Five-and-a-half-year-old, female, Siberian Husky dog. Example of ocular measurement as the average value resulting from the three different values obtained on the hotspot centered on the medial canthus of the eye and on two perpendicular lines, drawn from the dorsal to the ventral margin of the eye and from the ocular medial canthus to the lateral one. The brighter colors (red, orange, and yellow) indicate warmer temperatures (more heat and infrared radiation emitted), while the purples and dark blue/black indicate cooler temperatures (less heat and infrared radiation emitted). Moreover, all commas inserted in the measurements within the figure are indicated according to the Italian style, therefore they must be understood as points to indicate decimals following the British style (e.g., “33,9” in Italian style has to be intended as “33.9” following the British style). Sp = Spot. Li = Line. Regarding the other ROIs, elliptical areas corresponding to the main body regions were identified within each image, as well as lines (major axis of the ellipse) and points within the areas: the final surface temperature was obtained from the average of the measurements obtained in areas, lines and points (Figure 2).

Figure 2

Five-and-a-half-year-old, female, Siberian Husky dog. Pattern of measurement of left homobrachial region (OSX), thoraco-lumbar region and left dorsal portion of the ventro-lateral region of the abdomen (LSX) and left thigh region (CSX). For each ROI, the body surface temperature was measured using three techniques: by points of interest (A), by lines (B) and by areas (C). The brighter colors (red, orange, and yellow) indicate warmer temperatures (more heat and infrared radiation emitted), while the purples and dark blue/black indicate cooler temperatures (less heat and infrared radiation emitted). Moreover, all commas inserted in the measurements within the figure are indicated according to the Italian style, therefore they must be understood as points to indicate decimals following the British style. Sp = Spot. Li = Line. El = elliptical area.

Figure 3

Five-year-old, female, Siberian Husky dog. Comparison of macroscopic thermographic aspect of ocular image before (T0) and after competition (T1). The brighter colors (red, orange, and yellow) indicate warmer temperatures (more heat and infrared radiation emitted), while the purples and dark blue/black indicate cooler temperatures (less heat and infrared radiation emitted).

Figure 4

Five-year-old, female, Siberian Husky dog. Comparison of macroscopic thermographic aspect of left lateral view of the body surface before (T0) and after competition (T1). The brighter colors (red, orange, and yellow) indicate warmer temperatures (more heat and infrared radiation emitted), while the purples and dark blue/black indicate cooler temperatures (less heat and infrared radiation emitted). -2.0 = −2.0.