Ultrasonographic evaluation of adrenal gland thickness in dogs with hypoadrenocorticism and in sick dogs mimicking Addison's Disease

Abstract

Hypoadrenocorticism is an uncommon illness in dogs caused, in most cases, by an immune-mediated destruction of the adrenal cortex that lead to deficiency of glucocorticoids, mineralocorticoids, or both. The clinical signs are not pathognomonic, so it has been nicknamed as ‘the great pretender’ due to its ability to mimic other diseases. The purpose of this retrospective study was to assess the sensitivity and specificity of ultrasonography to detect adrenal gland findings consistent with canine hypoadrenocorticism and to compare adrenal gland thickness between dogs with hypoadrenocorticism and dogs mimicking hypoadrenocorticism based on different weight groups. The adrenal glands of 23 dogs with hypoadrenocorticism were assessed ultrasonographically and compared with those 28 dogs mimicking Addison disease. The thickness of both adrenal glands was measured on abdominal ultrasonography and the results for each group based on weight categories were compared. Statistical analysis revealed that both adrenal glands were thinner in dogs with hypoadrenocorticism than in sick dogs mimicking Addison’s disease. The overall sensitivity to detect hypoadrenocorticism was 95%, and the specificity was 75%. Therefore, the use of different thickness left, and right adrenal gland based on different weight categories can aid in the diagnosis of hypoadrenocorticism.