Selected clinicopathologic features of normal and exhausted endurance horses were evaluated during conditions of severe heat and work stress. The normal group of horses (Group A) manifested dehydration, hyponatremia, hypokalemia, and hypochloremia. The majority of the horses of Group A had a metabolic alkalosis and a hematologic pattern of response to stress. The data for the group of exhausted horses (Group B) were similar to that for the normal horses, except the majority of the horses of Group B were more severely dehydrated, and plasma potassium values were within the normal range. The acid-base parameters of Group B varied considerably, with the more severely affected horses having a partially compensated respiratory acidosis. Hematologically, horses of Group B had a significant left shift in addition to the stress response. The data are compared with previous reports along with a discussion of the physiologic processes responsible for the alterations observed.
ASJC Scopus subject areas
- Animal Science and Zoology