Abstract

Background:
Hyperkalemia has multiple etiologies, and although primary adrenocortical insufficiency is a well-known hormonal cause, hyperkalemia may also result from hyporeninaemic hypoaldosteronism, in which impaired renin secretion reduces aldosterone production and mineralocorticoid activity.

Case Description:
A 15-year-old spayed female Miniature Dachshund presented with persistent hyperkalemia. The dog exhibited systemic hypertension (systolic blood pressure: 192 mmHg) and mild renal insufficiency without evidence of urinary obstruction, hemolysis, cellular lysis, or potassium-sparing drug administration. An ACTH stimulation test revealed normal cortisol concentrations (pre: 4.3 µg/dL; post: 20.7 µg/dL), excluding primary hypoadrenocorticism. The plasma renin activity (PRA) and aldosterone concentration were evaluated. PRA was undetectable (

Key words: Aldosterone; Hyperkalaemia; Hyporeninaemic hypoaldosteronism; Renin; Type IV renal tubular acidosis.