Atypical Addison's disease in the dog: a retrospective survey of 14 cases

Fourteen dogs diagnosed with Addison's disease and having atypical serum electrolyte levels are described. Seventy-eight percent were female, and most showed signs of inappetence, weakness, or vomiting. Ninety-three percent of the cases had either hyponatremia without hyperkalemia or normal serum electrolyte concentrations. Hemogram features were variable and were not useful in suggesting a diagnosis of hypoadrenocorticism. The results of this study show that normal or mild serum electrolyte changes in a dog with clinical signs compatible with Addison's disease should not exclude this diagnosis from consideration. Definitive diagnosis depends on the demonstration of inadequate adrenocortical response to adrenocorticotropic hormone (ACTH) stimulation.