Blood oxygen binding in calves with naturally occurring diarrhea

Objective-To assess blood oxygen binding in calves with diarrhea. Animals-22 dairy and 26 double-muscled calves with diarrhea, 31 healthy dai ry carves and 37 healthy double-muscled calves. Procedure-Severity of disease, including the ability of affected calves to stand, was evaluated. Hydration and signs of depression were scored. Venous and arterial blood samples were collected, and 2,3-diphosphoglycerate, ATP , chloride, inorganic phosphate, lactate, pyruvate, total protein, albumin, and hemoglobin concentrations, and Hct, pH, PCO2, and PO2 were determined. Oxygen equilibrium curves (OEC) were constructed under standard conditions , and oxygen extraction ratios were calculated. Results-Recumbent calves of both breed-types were more dehydrated and had m ore severe signs of depression than ambulatory affected carves. In both bre ed-types, hemoglobin oxygen affinity was increased in calves with diarrhea, compared with healthy calves, as indicated by a decrease in standard parti al oxygen pressure (P50). Diarrhea induced hypocapnia and hypothermia in th e most severely affected calves, which counteracted the acidosis-induced ri ght shift in arterial and venous OEC. Arterial and venous P50 were signific antly less in double-muscled calves with diarrhea than healthy carves, wher eas P50 for affected dairy calves were similar to those of healthy calves. Except in the most severely affected dairy calves, oxygen extraction ratio was significantly less in carves with diarrhea, compared with healthy calve s. Conclusions and Clinical Relevance-Release of oxygen from blood may be impa ired in carves with diarrhea, depending on the effect of the disease on cer tain blood biochemical variables.