Effects of training and strenuous exercise on hematologic values and peripheral blood leukocyte subsets in racing sled dogs.
OBJECTIVE
To determine the effects of training and sustained submaximal exercise on hematologic values in racing sled dogs.


METHODS
Cohort study.


METHODS
39 Alaskan sled dogs bred for endurance racing. Procedures-Blood samples were collected prior to initiation of a 7-month training regimen (n=39), after completion of the training regimen (19), and after completion of an 1,100-mile race (9), and a CBC, differential cell count, and flow cytometry for leukocyte surface antigens were performed.


RESULTS
Both training and exercise caused significant decreases in PCV and hemoglobin concentration and significant increases in total WBC count. In contrast, training and exercise were not found to have significant effects on absolute numbers or fractions of CD4+ or CD8+ lymphocytes, other than a significant increase in the fraction of CD8+ lymphocytes associated with training.


CONCLUSIONS
Results suggested that training and exercise induced changes in several hematologic values in racing sled dogs. Extracellular fluid volume expansion was the likely explanation for the training-induced decrease in PCV, and acute blood loss secondary to gastrointestinal tract bleeding was likely responsible for the decrease in PCV associated with acute exercise.
Davis
Michael S
MS
Comparative Exercise Physiology Laboratory, 264 McElroy Hall, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Davis
William C
WC
Ensign
Wayne Y
WY
Hinchcliff
Kenneth W
KW
Holbrook
Todd C
TC
Williamson
Katherine K
KK
D000413:Alaska; D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D001774:Blood Chemical Analysis / Q000379:methods / Q000662:veterinary*; D018791:CD4 Lymphocyte Count / Q000662:veterinary; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes; D015331:Cohort Studies; D004285:Dogs / Q000097:blood* / Q000502:physiology*; D004906:Erythrocyte Count / Q000662:veterinary; D005260:Female; D005434:Flow Cytometry / Q000379:methods / Q000662:veterinary*; D006403:Hematologic Tests / Q000662:veterinary; D007958:Leukocyte Count / Q000662:veterinary; D007962:Leukocytes / Q000166:cytology; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012420:Running; D013177:Sports