title: Primary hyperaldosteronism: expanding the diagnostic net.
abstract: BACKGROUND
  Primary hyperaldosteronism is probably the most common adrenocortical disorder in cats. As in humans, it is often unrecognised, which excludes a potentially large number of cats from appropriate treatment.
  
  
  METHODS
  Affected cats present at a median age of 13 years (range 5-20 years). A breed or sex predilection has not been documented. The excessive secretion of mineralocorticoids usually leads to hypokalaemia and/or systemic arterial hypertension. Most affected cats present with muscular weakness and/or ocular signs of arterial hypertension.
  
  
  METHODS
  In any cat presenting with hypokalaemia and/or arterial hypertension, other potential causes should be excluded. The ratio of plasma aldosterone concentration to plasma renin activity (aldosterone:renin ratio) is currently the best screening test for feline primary hyperaldosteronism. Diagnostic imaging is required to differentiate between adrenocortical neoplasia and bilateral hyperplasia, and to detect any distant metastases.
  
  
  OBJECTIVE
  The differentiation between adrenocortical neoplasia and bilateral hyperplasia is imperative for planning optimal therapy, but the limited sensitivity of diagnostic imaging may occasionally pose a problem. For confirmed unilateral primary hyperaldosteronism, unilateral adrenalectomy is the treatment of choice, and offers an excellent prognosis, but potentially fatal intra- and postoperative haemorrhage is a reported complication and risk factors have yet to be identified.
  
  
  METHODS
  Only a few case reports are available on which to base the optimal diagnostic and therapeutic approach to feline primary hyperaldosteronism. This article reviews the physiology of aldosterone production and the pathophysiology of primary hyperaldosteronism, and summarises the currently available literature on the feline disease. Practical suggestions are given for the diagnostic investigation of cats with suspected primary hyperaldosteronism.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. s.c.djajadiningrat@uu.nl
authors.forename: Sylvia
authors.initials: S
authors.lastname: Djajadiningrat-Laanen
authors.forename: Sara
authors.initials: S
authors.lastname: Galac
authors.forename: Hans
authors.initials: H
authors.lastname: Kooistra
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D002415:Cats; D003937:Diagnosis, Differential; D005260:Female; D006929:Hyperaldosteronism / Q000150:complications / Q000175:diagnosis / Q000662:veterinary*; D006973:Hypertension / Q000209:etiology / Q000662:veterinary; D007008:Hypokalemia / Q000209:etiology / Q000662:veterinary; D014463:Ultrasonography