TITLE:
The Effects of Low Intensity Endurance Activity on Various Physiological Parameters and Exercise Induced Oxidative Stress in Dogs
AUTHORS:
Janice L. Huntingford, Corri B. Levine, Debbie J. Mustacich, Devin Corrigan, Robert L. Downey, Joseph J. Wakshlag
KEYWORDS:
Exercise, Cortisol, Isoprostane, Dehydration, Uric Acid
JOURNAL NAME:
Open Journal of Veterinary Medicine,
Vol.4 No.7,
July
29,
2014
ABSTRACT: The study of canine
athlete physiology has focused on endurance sled dog racing and high intensity
short duration Greyhound racing, yet the number of dogs competing in low
intensity endurance activities is rising due to the increased numbers of
hunting and companion dog activities. There is little information on the
physiological effect of longer duration low intensity endurance activities. We
set out to evaluate the serum biochemistry, oxidative stress, and cortisol
response before and after two consecutive days of exercise in ten healthy unconditioned
male dogs. Exercise sessions consisted of 120 minutes on an exercise wheel at 11
km/hour on 2 consecutive days. Blood was collected at four time points: 24 hours
pre-exercise (sample 1, Day 0, resting); 2 min post-exercise on days 1 and 2,
(samples 2 and 3, respectively); and 20 hours post-exercise, collected on day
3(sample 4). Hematocrit, blood gases, serum chemistry, uric acid, cortisol, and
F2-isoprostanes were determined. Serum biochemistry and hematocrit
suggested hemoconcentration, mild muscle damage and respiratory alkalosis
during exercise, which was expected in the unconditioned canine athlete. In
addition, plasma indices of oxidative damage (F2-isoprostanes)
increased, as did plasma uric acid (an endogenous antioxidant). Importantly,
similar to human studies, plasma F2-isoprostanes decreased 24 hours
after exercise suggesting a protective effect of exercise. Serum cortisol
concentrations were also markedly elevated at the end of exercise on both days
suggesting that timing of sampling may play a role in interpreting cortisol
results when looking at previous field studies.