A condition of primary hyperaldosteronism resulting from an adrenal tumor i
n two cats is presented and was characterized by hypertension, hypokalemia,
inappropriate kaliuresis, low normal plasma renin activity, and markedly i
ncreased serum aldosterone concentration. One of the two cats underwent a l
aparotomy, and in this case hypertension and hypokalemia resolved following
the removal of an adrenal tumor.