Infrared thermography in clinically healthy dogs shows body region and haircoat variability.

Infrared thermography quantifies body surface temperature with growing applications in dogs, particularly among rehabilitation practitioners; however, incomplete understanding of normal temperature variation in healthy dogs limits interpretation. This study characterized body surface temperature distribution and evaluated factors influencing thermographic measurements in a heterogeneous group of healthy dogs. Client-owned, adult dogs were prospectively enrolled and underwent standardized thermographic imaging, with regions of interest defined for trunk, neck, and spine. Mean surface temperatures were assessed for symmetry, compared across regions and explored for relationships with individual dog characteristics. p < 0.05 was significant with adjustment for multiple comparisons. Thirty-three dogs were included with median age of 3.3 (1.0-10.9) years and median body weight of 18.6 (3.7-59.4) kgs. No significant left-right asymmetry was identified in paired regions. Mean (± SD) surface temperature for the dorsal neck (23.9° ± 1.6°) was significantly cooler than the lumbar spine (25.4° ± 1.9°, p = 0.009) and lateral trunk (25.2° ± 2.0°, p = 0.03) regions. Short-haired dogs exhibited significantly higher values than medium/long-haired dogs for the lateral trunk (26.8° ± 1.9° vs. 24.2° ± 1.4°, p = 0.001), dorsal neck (25.2° ± 1.8° vs. 23.2° ± 0.9°, p = 0.01) and sacral (26.0° ± 2.2 °C vs. 23.5° ± 1.1 °C, p = 0.006) regions. No other significant relationships were identified. Regional variation and coat length are important factors influencing thermography in healthy dogs, while bilateral symmetry is generally preserved. Establishing variability in healthy dogs is critical to clinical interpretation of thermography in abnormal dogs.