Unanticipated hyperkalaemia

[...]most of the blood samples have been taken after a period of presumed decreased cardiac output, which may have contributed to the pH derangement and so the relationship between the elevated potassium concentration and decreased pH is not clear. The dogs have not had any underlying urinary tract disease, and, in cases with baseline blood samples available for comparison, the rate of increase in plasma potassium concentration is consistent with efflux of potassium from the intracellular to extracellular space.