Hypoadrenocorticism in a family of leonbergers.

Hypoadrenocorticism was diagnosed in four related leonbergers. Two of the four dogs also had low-resting serum thyroxine (T4) levels and signs consistent with hypothyroidism. The familial association of the affected dogs and the presence of coexisting thyroid dysfunction are similar to what is seen in human type II polyglandular autoimmune syndrome.