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  • Author or Editor: Guilherme C. Ferraz x
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Abstract

Objective—To investigate the effect of acute administration of caffeine on the athletic performance of Arabian horses.

Animals—12 healthy adult Arabian horses that were trained for exercise on a treadmill.

Procedures—By use of a crossover study design, horses received each of the following treatments: IV administration of caffeine (5 mg/kg) and IV administration of approximately the same volume of saline (0.9% NaCl) solution. Order of treatment was randomized, and there was a 10-day interval between treatments. Thirty minutes after treatments, horses underwent an incremental exercise test (IET) on a treadmill. Blood samples were collected 15 seconds before the end of each velocity step of the IET for determination of blood lactate, blood glucose, plasma cortisol, and plasma insulin concentrations. Heart rate and hematologic variables were also analyzed.

Results—Velocities achieved when heart rates were 180 and 200 beats/min increased significantly in caffeine-treated horses, compared with control horses. Velocities corresponding to blood lactate concentrations of 4 and 2 mmol/L decreased significantly in caffeine-treated horses, compared with control horses. In comparison between groups, insulinemia was greater in control horses and glycemia was greater in caffeine-treated horses. Plasma cortisol concentration was significantly lowered by treatment with caffeine.

Conclusions and Clinical Relevance—IV administration of caffeine at 5 mg/kg improved the performance of Arabian horses during intense exercise of short duration and diminished the oxidative metabolism of glucose.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To determine whether the lactate threshold of dogs could be determined by a visual method and to assess the extent of agreement and bias among treadmill velocities for the lactate threshold as determined by visual (LTv) and polynomial (LTp) methods, glucose threshold as determined by visual (GTv) and polynomial (GTp) methods, and heart rate deflection point (HRdp) as a method for estimating the aerobic capacity of dogs.

ANIMALS 18 healthy adult Beagles.

PROCEDURES Each dog underwent a standardized incremental treadmill exercise test once. The test ended when the dog began to show signs of fatigue. Plasma lactate and glucose concentrations and heart rate (HR) were plotted against exercise intensity (treadmill velocity) for the duration of the test, and the LTv, GTv, and HRdp were determined visually. The LTp and GTp were determined by means of a second-order polynomial function. One-way ANOVA, Pearson correlation, Bland-Altman analyses, and ordinary least products regression were used to assess the extent of agreement and bias among the various threshold velocities.

RESULTS Mean velocity did not differ significantly among the thresholds evaluated. There was a strong positive correlation between the LTv velocity and the velocity for GTv (r = 0.91), LTp (r = 0.96), GTp (r = 0.94), and HRdp (r = 0.95).

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that LTv could be determined for dogs undergoing intense exercise on a treadmill, and the treadmill velocity corresponding to the LTv was associated with the velocity for the other hallmarks of endurance. Thus, that method may be useful for prescription and evaluation of conditioning programs for dogs.

Full access
in American Journal of Veterinary Research