Presumptive nontraumatic adrenal hemorrhage preceding hypoadrenocorticism in a dog

Nontraumatic adrenal hemorrhage (NTAH) has been associated with stress-induced catecholamines release in underlying conditions such as sepsis and recent surgery in humans. It can lead to primary hypoadrenocorticism (HOAC) when both adrenal glands are involved, with nonspecific clinical signs and laboratory findings that can lead to a missed diagnosis. Bilateral thickening of the adrenal glands with periadrenal fat stranding was identified in a 10-year-old male Maltese dog after abdominal surgery. The dog showed clinical signs and biochemical changes consistent with HOAC, but treatment for presumed critical illness-related corticosteroid insufficiency was initiated. Clinical signs relapsed with a 3-week dose reduction of hydrocortisone, and a reduction in adrenal size was observed on follow-up ultrasound examination. Hormonal testing confirmed HOAC in the dog. To the best of our knowledge, HOAC caused by spontaneous NTAH has not been reported in the veterinary literature. This report describes a dog that developed HOAC with presumed adrenal atrophy after suspected spontaneous bilateral NTAH.