Ultrasonographic and Thermographic Evaluation in Brachycephalic Dogs Before and After Physical Exercise in the Brazilian Northeast Semi-Arid Region

Brachycephalic dogs are predisposed to respiratory and thermoregulatory impairment, which may become evident during physical exertion. This study evaluated thermal and pulmonary ultrasonographic responses to standardized submaximal treadmill exercise in 41 clinically healthy brachycephalic dogs. Rectal temperature and infrared thermographic measurements of the ocular and facial regions were obtained before and immediately after exercise. Thoracic ultrasonography was performed at baseline and after a standardized 20-min post-exercise recovery period. The dogs walked on a treadmill at 1.3 m/s, with a 0° incline, for up to 6 min. Rectal temperature increased significantly after exercise (p < 0.0001), and significant changes were also observed in ocular thermographic regions R1 and R2 (p < 0.0001), whereas facial surface temperature did not differ significantly. No pulmonary ultrasonographic abnormalities were detected at baseline; after exercise, abnormalities were identified in 30/41 dogs (73%), including B-lines, pleural irregularity, pleural thickening, and, less frequently, discrete pleural effusion. These findings demonstrate measurable thermal responses and pleuropulmonary ultrasonographic changes following standardized submaximal exercise in brachycephalic dogs. Infrared ocular thermography and thoracic ultrasonography may provide complementary, non-invasive information for monitoring exercise-associated responses; however, the relationship between ocular and core body temperatures and the temporal and clinical significance of the pulmonary findings require further investigation.