Autoimmune polyendocrine syndrome with hypoadrenocorticism and diabetes mellitus in a dog: A rare case

Background Autoimmune polyendocrine syndrome, also called polyglandular autoimmune syndrome, is a rare immune‐mediated disorder that involves various endocrine glands. Purpose To report autoimmune polyendocrine syndrome in a dog. Methods A 9‐year‐old spayed female miniature poodle diagnosed with insulin‐dependent diabetes mellitus emergently visited our clinic for anorexia, severe depression, and vomiting. Hyponatremia, hypochloridemia, and recurrent hypoglycaemia were found. Hypoadrenocorticism was diagnosed based on consistent clinical signs and repeated adrenocorticotropic hormone stimulation tests. Results After injecting deoxycorticosterone pivalate and increasing the oral prednisolone dose, the patient's systemic condition improved. Conclusions To the best of our knowledge, this is the first case report of hypoadrenocorticism concurrent with diabetes mellitus in a dog. Furthermore, we would like to present the probability of an immune‐mediated disorder with multiple organs involved, like type IV autoimmune polyendocrine syndrome in humans. This is the first reported case of hypoadrenocorticism concurrent with diabetes mellitus in a dog. Considering that it has not only the characteristics of type II APS, but also characteristics of IBD, GNP, and IMP, the patient is considered for type IV APS diagnosis. This case highlights the importance of being vigilant about new components of a syndrome.