The influence of high-intensity moderate duration exercise on cardiac troponin I and C-reactive protein in sled dogs.

Abstract

BACKGROUND: C-reactive protein (CRP) and cardiac troponin I (cTnI) are biomarkers of systemic inflammation and cardiac damage, respectively. OBJECTIVE: To investigate the effects of short-duration high-intensity exercise on plasma cTnI and serum CRP concentrations in sprint racing sled dogs. ANIMALS: Twenty-two Alaskan sled dogs of 2 different teams participating in a 2-day racing event. METHODS: 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. RESULTS: There was a mild, significant rise (P<.01) in median cTnI concentrations from resting (0.02&#x2003;ng/mL; 0.0-0.12&#x2003;ng/mL) on both days after racing (day 1=0.06, 0.02-0.2&#x2003;ng/mL; day 2=0.07, 0.02-0.21&#x2003;ng/mL). Serum CRP concentrations showed a mild significant increase (P<.01) on day 2 after racing mean (9.2&#xb1;4.6&#x2003;&#x3bc;g/mL) as compared with resting (6.5+4.3&#x2003;&#x3bc;g/mL) and day 1 after racing (5.0+2.9&#x2003;&#x3bc;g/mL). Neither cTnI or CRP concentrations exceeded the upper reference range for healthy dogs. CONCLUSIONS AND CLINICAL RELEVANCE: 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.