Physiologic responses in healthy Labrador Retrievers during field trial training and competition

Ten healthy Labrador Retrievers (4 females and 6 males aged 3-6.5 years [mean, 4.5 years]) training with a professional trainer were studied. The dogs were in training during the entire study. Dogs were monitored within 5 minutes after retrieving birds on land and in water on 2 consecutive days during training and on 2 consecutive days at the Atlanta Retriever Club Fall Field Trial. Baseline samples were taken in the morning on a separate day before the dogs were loaded onto a truck. Venous samples were analyzed with a portable blood analyzer. Measurements included hematocrit, sodium, potassium, chloride, blood urea nitrogen (BUN), glucose, lactate, blood pH, Pco2, Po2, HCO3, and TCO2 plus rectal temperature, pulse rate, and respiratory rate. Ambient temperatures were recorded. Distances and times were estimated. Compared to baseline, significant increases occurred in rectal temperature, pulse rate, respiratory rate, chloride, lactate, and pH postexercise (P < .05): sodium, potassium, BUN, Pco2, and TCO2 were significantly decreased postexercise. Blood pH was markedly higher after retrieves on land than after retrieves in water. Estimated mean speeds were 11.4 mph (18.3 km/h) during a triple retrieve on land and 5.6 mph (9.0 km/h) during a retrieve in water. Maximal ambient temperatures were 84-86 degrees F (29-30 degrees C). In summary, Labrador Retrievers training with a professional trainer had evidence of hyperthermia, respiratory alkalosis, hypocapnia, and mild metabolic acidosis monitored within 5 minutes postexercise during training and field trial competition when maximal ambient temperatures were 85 degrees F (29 degrees C). The results provide a baseline against which physiologic responses of dogs with poor performance can be compared.