Hypoadrenocorticism

Question 1

• What hormone(s) are deficient in primary hypoadrenocorticism?

Answer 1

Aldosterone and cortisol

Question 2

• What are the types of hypoadrenocorticism?

Answer 2

Primary – loss of adrenal cortex
Secondary – deficiency of ACTH, therefore only effects cortisol
Iatrogenic – exogenous steroids -> adrenal atrophy

Question 3

• What pathophysiologic effects do these deficiencies cause?

Answer 3

Cortisol causes weakness, gastrointestinal signs, anaemia and hypotension
Aldosterone deficiency causes sodium & fluid loss, and hyperkalaemia (which causes heart problems)

Question 4

• What is a typical signalment of a patient with Addison’s disease?

Answer 4

Female, young to middle-aged, any breed dog

Question 5

• What are typical clinical signs of Addison’s disease?

Answer 5

No typical signs, may be episodic, may be chronic GI signs, “poor doer”, PU/PD, or may present collapsed in shock

Question 6

• What are some abnormal laboratory findings (CBC, chemistry profile) in Addisonian patients?

Answer 6

Relative eosinophilia, lymphocytosis, anaemia

Increased potassium, decreased sodium and chloride

Question 7

• What changes might be seen on an ECG?

Answer 7

Bradycardia, peaked T waves, widened QRS complexes, disappearance of P waves

Question 8

• How is primary hypoadrenocorticism definitively diagnosed?

Answer 8

ACTH stimulation test demonstrating low cortisol and aldosterone levels with no response