Pattern of physiologic effects of adrenalectomy in the dog

Adrenalectomized dogs were observed in order to identify the patterns of physiologic changes occurring during development of adrenocortical insufficiency. Daily measurements included plasma concentrations of sodium and potassium, arterial blood pH, packed cell volume, heart rate, and selected components of the electrocardiogram (ECG). The pattern in which these measurements changed indicated that alterations in plasma concentrations of sodium and potassium, T-wave configuration, and QRS interval were more consistent, whereas alterations in P-wave configuration were not evident until approach of terminal stages.