Evaluation of Aldosterone Concentrations in Dogs with Hypoadrenocorticism. (15th November 2013)

• Record Type: Journal Article
• Authors: Baumstark, M.E.; Sieber‐Ruckstuhl, N.S.; Müller, C.; Wenger, M.; Boretti, F.S.; Reusch, C.E.
• Is Part Of: Journal of veterinary internal medicine. Volume 28:Number 1(2014:Jan./Feb.)
• Page Start: 154
• Page End: 159
• Publication Date: 2013-11-15
• Subjects: Veterinary medicine -- Periodicals; 636.0896
• DOI: 10.1111/jvim.12243
• Languages: English
• ISSNs: 0891-6640

Abstract

<abstract abstract-type="main" id="jvim12243-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jvim12243-sec-0001" sec-type="section"> <title>Background</title> <p>Some dogs with primary hypoadrenocorticism (HA) have normal sodium and potassium concentrations, a phenomenon called atypical Addison's disease. The assumption that the zona glomerulosa and aldosterone secretion in these dogs are normal seems widely accepted; however, aldosterone measurements are missing in most published cases.</p> </sec> <sec id="jvim12243-sec-0002" sec-type="section"> <title>Objectives</title> <p>To measure aldosterone in dogs with HA with and without electrolyte abnormalities and to determine the time point of aldosterone peak concentrations during ACTH stimulation.</p> </sec> <sec id="jvim12243-sec-0003" sec-type="section"> <title>Animals</title> <p>Seventy dogs with HA, 22 dogs with diseases mimicking HA, and 19 healthy dogs.</p> </sec> <sec id="jvim12243-sec-0004" sec-type="section"> <title>Methods</title> <p>Prospective study. Blood samples were taken before and 60 minutes after injection of 250 μg ACTH in all dogs. Additional blood samples were taken 15, 30, and 45 minutes after ACTH in 7 dogs with HA and in 22 with diseases mimicking HA.</p> </sec> <sec id="jvim12243-sec-0005" sec-type="section"> <title>Results</title> <p>Baseline and ACTH‐stimulated aldosterone was significantly lower in dogs with HA than in the other groups. Aldosterone was low or undetectable in 67/70 dogs with HA independently of sodium and potassium levels. In 3 dogs, sodium/potassium concentrations were normal; in 1 dog, sodium was normal and potassium decreased. In all 4, ACTH‐stimulated aldosterone concentrations were below the detection limit of the assay. Aldosterone concentrations were not different at 30, 45, or 60 minutes after ACTH administration.</p> </sec> <sec id="jvim12243-sec-0006" sec-type="section"> <title>Conclusion and Clinical Importance</title> <p>Cortisol and aldosterone secretion is compromised in dogs with HA with and without electrolyte abnormalities. The term atypical Addison's disease, used for dogs with primary HA and normal electrolytes, must be reconsidered; other mechanisms allowing normal electrolyte balance without aldosterone should be evaluated in these dogs.</p> </sec> </abstract>