Urinary aldosterone to creatinine ratio in cats before and after suppression with salt or fludrocortisone acetate

• Published in: Journal of veterinary internal medicine 2008-11, Vol.22 (6), p.1283-1288
• Main Authors: Djajadiningrat-Laanen, S.C, Galac, S, Cammelbeeck, S.E, Laar, K.J.C. van, Boer, P, Kooistra, H.S
• Format: Article
• Language: English
• Subjects: Adrenal cortex; aldosterone; Aldosterone - urine; Animals; Cat Diseases - drug therapy; Cat Diseases - urine; Cats; Conn's syndrome; creatinine; Creatinine - urine; diagnostic techniques; endocrine diseases; Feline; Female; Fludrocortisone - pharmacology; Hyperaldosteronism - drug therapy; Hyperaldosteronism - urine; Male; normal values; Primary hyperaldosteronism; sodium chloride; Sodium Chloride - pharmacology; urine
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/j.1939-1676.2008.0166.x

Background: The endocrine diagnosis of primary hyperaldosteronism in cats currently is based on an increased plasma aldosterone to renin ratio, which has several disadvantages for use in veterinary practice. Objectives: To establish a reference range for the urinary aldosterone to creatinine ratio (UACR) and to determine whether oral administration of either sodium chloride or fludrocortisone acetate is effective for use in a suppression test. Animals: Forty‐two healthy cats from an animal shelter and 1 cat with primary hyperaldosteronism from a veterinary teaching hospital. Methods: Morning urine samples for determination of the basal UACR were collected from 42 healthy cats. For the suppression tests, urine samples for the UACR were collected after twice daily oral administration for 4 consecutive days of either sodium chloride, 0.25 g/kg body weight (n = 22) or fludrocortisone acetate, 0.05 mg/kg body weight (n = 15). Results: The median basal UACR was 7.2 × 10−9 (range, 1.8–52.3 × 10−9), with a calculated reference range of