Canine Hyperadrenocorticism – a few take home messages
- Based on the 2013 ACVIM/ECVIM consensus statement, a dog should be tested for hyperadrenocorticism only when clinical signs consistent with the disease are present. The screening test of choice for the diagnosis of hyperadrenocorticism is the low dose dexamethasone test (LDDST) as it has higher sensitivity (85-100%) compared with other tests.
- Most common laboratory changes associated with hyperadrenocorticism include: elevated ALP and ALT levels, hypercholesterolaemia, hypertriglyceridemia, hyperglycaemia, lymphopenia and eosinopenia.
- When the diagnosis of hyperadrenocorticism is made, further differentiation into pituitary dependent (PDH) and adrenal dependent (ADH) forms can be achieved by performing a high dose dexamethasone suppression test (HDDST), measurement of endogenous ACTH, and/or imaging studies (e.g. ultrasound/CAT/MRI).
- ACTH stimulation test is considered less sensitive than LDDST. However, it is a quick test to perform (1 hour) and is the test of choice if iatrogenic hyperadrenocorticism is suspected or for monitoring purposes.
- It is not uncommon to see dogs with multiple endocrinopathies, in particular hyperadrenocorticism and diabetes mellitus. In those cases, it is recommended trying to get the best control of diabetes mellitus before testing for hyperadrenocorticism, to avoid false positive results due to stress.