Cardiovascular Response to Treadmill Exercise in Mongrel Dogs in Lagos State

Understanding cardiovascular adaptation to physical exercise in dogs is important for sports veterinary medicine, as well as for developing exercise tolerance protocols for post-surgical recovery. Despite the large population of working and companion dogs in Lagos State, South West Nigeria, there is limited data on exercise-induced cardiovascular changes in locally maintained mongrel dogs. This study measured heart rate, systolic blood pressure, respiratory rate, and rectal temperature in 30 clinically healthy adult mongrel dogs before, during, and after a standardised treadmill exercise protocol. Animals were acclimatised to the treadmill for one week before the experiment commenced. Exercise involved walking at 3 km/h for 10 minutes followed by running at 6 km/h for 10 minutes. Cardiovascular parameters were recorded at rest, at 5 and 10 minutes of walking, at 5 and 10 minutes of running, and at 5, 15, and 30 minutes of recovery. Heart rate increased significantly from a resting mean of 88 beats per minute to 154 beats per minute at peak exercise. Systolic blood pressure rose from 128 mmHg to 162 mmHg during running. Both parameters returned to baseline within 15 minutes of cessation of exercise. Respiratory rate tripled during peak exercise. No arrhythmias were detected by auscultation. These findings document normal physiological responses to moderate exercise in Nigerian mongrel dogs and provide reference data for clinical exercise testing. Keywords: cardiovascular, exercise, dogs, heart rate, blood pressure.