Related Experiment Video
Updated: Oct 15, 2025
Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids
Published on: April 25, 2016
Evaluation of urine electrolytes for the diagnosis of hypoadrenocorticism in dogs
Casey A Dropkin1, John M Kruger1, Daniel K Langlois1
1Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA.
Background:
Most dogs with primary hypoadrenocorticism (HA) have a mineralocorticoid deficiency, which decreases renal tubular sodium reabsorption and potassium excretion. Limited information is available concerning the clinical value of measuring urine electrolytes to aid in an HA diagnosis.
Objectives:
We aimed to evaluate the diagnostic utility of urine electrolyte measurements in dogs with HA.
Methods:
Urine sodium and potassium concentrations were measured in 89 dogs, including 39 dogs with HA and 50 controls with nonadrenal illness. Fractional excretions of sodium (FENa ) and potassium (FEK ) were also calculated. Urine electrolytes and fractional excretion values were compared between the groups. Sensitivities and specificities were determined for various cut-points.
Results:
The median urine sodium to potassium (Na:K) ratio was twofold greater (P < .001), and median FENa was fourfold greater (P < .001) in HA dogs as compared with controls. However, no cut-point for any variable with >90% sensitivity or specificity provided a corresponding specificity or sensitivity of >50%. When only dogs with abnormal serum or plasma electrolytes were included in the analyses, absolute urine electrolyte concentrations and FENa were not different between study populations (P > .05 for all comparisons), but the FEK was increased (P = .005) and the urine potassium:creatinine ratio was decreased (P < .001) in the control dogs compared with the dogs with HA.
Conclusions:
Urine electrolyte concentrations and fractional excretions are altered in dogs with HA. However, substantial overlap exists with control dogs with nonadrenal illness. Therefore, these values are unlikely to have diagnostic utility for dogs with HA.
Related Concept Videos
01:27Adrenal Gland Disorders
Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing...
01:24Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
01:29Urine Studies I: Urinalysis
01:20Physiology of the Genitourinary System III: Urine Concentration and Dilution
01:24Diagnosing Acidosis and Alkalosis
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2 and...
01:31Hormones of the Adrenal Glands
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and...