Effect of increased dietary protein and decreased dietary carbohydrate on performance and body composition in racing Greyhounds.

Objective—To determine effects of increased dietary protein and decreased dietary carbohydrate on hematologic variables, body composition, and racing performance in Greyhounds. Animals—8 adult Greyhounds. Procedure—Dogs were fed a high-protein (HP; 37% metabolizable-energy [ME] protein, 33% ME fat, 30% ME carbohydrate) or moderate-protein (MP; 24% ME protein, 33% ME fat, 43% ME carbohydrate) extruded diet for 11 weeks. Dogs subsequently were fed the other diet for 11 weeks (crossover design). Dogs raced a distance of 500 m twice weekly. Rectal temperature, hematologic variables before and after racing, plasma volume, total body water, body weight, average weekly food intake, and race times were measured at the end of each diet period. Results—When dogs were fed the MP diet, compared with the HP diet, values (mean ± SD) differed significantly for race time (32.43 ± 0.48 vs 32.61 ± 0.50 seconds), body weight (32.8 ± 2.5 vs 32.2 ± 2.9 kg), Hct before (56 ± 4 vs 54 ± 6%) and after (67 ± 3 vs 64 ± 8%) racing, ...