[Evaluation of endogenous aldosterone concentrations and thyroid parameters in dogs with hypoadrenocorticism - a...

The evaluation of the prevalence of hypoaldosteronism and (autoimmune) hypothyroidism in dogs with hypoadrenocorticismLeft over serum samples from 29 dogs with confirmed hypoadrenocorticism were analyzed. Aldosterone concentrations were determined in 0 h- and 1 h samples of the ACTH-stimulation test. Total T4 concentration (TT4), thyroid-stimulating hormone (TSH) and thyroglobuline antibodies (TgAA) were determined at 0 h and 1 h following the administration of ACTH. Patient data base was searched retrospectively for data on neutrophil-to-lymphocyte ratio as well as sodium (Na), potassium (K), the Na:K ratio and creatinine concentrations.Hypoaldosteronism was detected in 59% (17/29) of dogs with electrolyte imbalances. The aldosterone concentration correlated with the Na:K ratio. Physiologic aldosterone concentrations were identified in 10% (3/29) of patients with electrolyte imbalances. Thyroid parameters suggesting hypothyroidism (low TT4, high TSH) were identified in 10% (3/29) of the study population. Additionally, 2 of these dogs had increased TgAA levels. Three dogs showed increased TSH levels while TT4 was within the reference range.Aldosterone is decreased in most patients with hypoadrenocorticism. Thyroid parameters should be interpreted with care in dogs diagnosed with hypoadrenocorticism.