Dz of the Adrenals Flashcards
Adrenal gland cortex
Glomerulosa: aldosterone
Fasciculata: cortisol, sex hormones
Reticularis: androgen, some cortisol
Function of the adrenal cortex
Glucocorticoid regulation (neg feedback regulation CRH and ACTH)
Aldosterone regulation (osmoreceptors, RAAS, K+ levels)
Medulla
Catecholamines
Primary hypoadrenocorticism
Immune-mediated destruction of adrenal cortices
Usually bilateral
Drug induced hypoadrenocorticism
Mitotane and trilostane
Other causes of hypoadrenocorticism
Iatrogenic
Thromboembolism/ loss of blood supply
Infiltrative neoplasia
Amyloidosis
Signalment of hypoadrenocorticism
Young to middle-aged female dogs (intact>)
Poodles, collies, westie terriers, danes, rotties
Hx of patients with hypoadrenocorticism
Waxing and waning (on and off)
+/- V/D responsive to fluids, abx and steroids
Weakness and leth
CS associated with hypoadrenocorticism
Depression, leth, weakness, anorexia, dehy
PU/PD, bradycardia, abdominal pain, regurg. hypotension, acute collapse
CBC of hypoadrenocorticism
Anemia of chr. dz
Marked anemia secondary to GI hemorrhage
+/- hyperproteinemia
Reverse stress leukogram
Chemistry of hypoadrenocorticism
Hypo-natremia,-cholermia, -glycemia, -albuminemia
Hyper-kalemia, calcemia
Na:K <25:1
Azotemia (dehy/ hypotension- ↓ GFR, upper Gi hemorrhage)
Atypical addison’s
Electrolyte changes won’t occur
Gluco deficient and normal aldosterone
UA of hypoadrenocorticism
Low USG due to PU/PD
May ↑ with dehy (if medullary washout not occured)
ECG changes with hypoadrenocorticism
Hyperkalemia induced changes →bradycardia, tall T waves, wide QRS, flat P waves → atrial standstill
Diagnostic imaging of hypoadrenocorticism
Rads: hypovolemia maybe megaesophagus
U/S: adrenals small or poorly visualized
ACTH stimulation test
Definitive for hypoadrenocorticism
If pre and post <1 = diagnostic
Not addison’s if 2x the baseline cortisol