The Influence of High-Intensity Moderate Duration Exercise on Cardiac Troponin I and C-Reactive Protein in Sled Dogs

Abstract

C-reactive protein (CRP) and cardiac troponin I (cTnI) are biomarkers of systemic inflammation and cardiac damage, respectively. To investigate the effects of short-duration high-intensity exercise on plasma cTnI and serum CRP concentrations in sprint racing sled dogs. Twenty-two Alaskan sled dogs of 2 different teams participating in a 2-day racing event. In this prospective field study, cephalic venipuncture was performed on all dogs before racing and immediately after racing on 2 consecutive days. Plasma cTnI and serum CRP concentrations were evaluated at each time point. There was a mild, significant rise (P<.01) in median cTnI concentrations from resting (0.02 ng/mL; 0.0-0.12 ng/mL) on both days after racing (day 1=0.06, 0.02-0.2 ng/mL; day 2=0.07, 0.02-0.21 ng/mL). Serum CRP concentrations showed a mild significant increase (P<.01) on day 2 after racing mean (9.2±4.6 μg/mL) as compared with resting (6.5+4.3 μg/mL) and day 1 after racing (5.0+2.9 μg/mL). Neither cTnI or CRP concentrations exceeded the upper reference range for healthy dogs. Strenuous exercise of short duration did not result in cTnI concentrations above the reference range for healthy dogs. Although increased after 2 days of short-duration strenuous exercise, CRP did not reach concentrations suggestive of inflammation, as reported previously in the endurance sled dogs. Therefore, we surmise that moderate exercise does not present a confounding variable in the interpretation of cTnI and CRP concentrations in normal dogs.