Hypoadrenocorticism Flashcards
Hypoadrenocorticism
syndrome of adrenal insufficiency resulting form diseas affecting both adrenal cortices
Clinical syndrome fo anemaic, general langour, debility, remarkable feebleness, of the hearts action and irritability of the stomach
Ultimatley FATAL disease
Hypoadrenocorticism
Defined by
Location of disease: primary, secondary
Type of Hormone missing: Typical - gluco + mineral
Atypical - Glucocorticoid only
Primary Hypoadrenocorticism (Addison’s disease)
Most common
Due to Atrophy or destruction of all layer cortex, immune-mediated destruction and atrophy
Rare causes - granulomatous, amyloidosis, infarction, hemorrhage, and metastatic disease
Iatrogenic - mitotane
Deficiency in Cortisol
anorexia, weight loss
lethargy
hypoglycemia
gastrointestinal signs
Deficiency in Aldosterone
Hyponatremia, hypochloremia, hyperkalemia
decreased plasma volume - water loss
Atypical Addison’s
Glucocorticoid deciciency ONLY
signs consistent with glucocorticoid deficiency initially
last cells destroyed typically the glomerulosa
Expect to progress to mineralocorticoid deficiency too
Secondary hypoadrenocorticism
UNCOMMON / RARE in dogs
Reduced secretion of ACTH by pituitary gland or CRH by the hypothalamus
Due to:
Neoplasia
trauma
inflammation
Iatrogenic
Canine Addison’s Disease
(hypoadrenocorticism)
Signalment
Young to middle-aged dog
females overrepresented
any breed including mixed breeds can be affected
Canine Addisons disease
hypoadrenocorticism
clinical signs
must have >85% loss of adrenocortical cells before clinical signs are obvious
In early stages of disease, basal hormone secretion is usually sufficint unless stressed
Most common complaints:
anorexia/hyporexia
lethargy/depression
vomiting/diarrhea
polyuria
weakness
weight loss
Occasionally regurgitation or abdominal discomfort may be reported
Canine addisons disease
hyperadreocorticism
Addisonian Crisis
later course of disease/severe signs/life threatening
Bradycardia
hypovolumia
weak pulses
hypothermia
shock
melena
collapse
Canine Addisons disease
Hypoadrenocorticism
Diagnosis:
CBC
mild normocytic, normochromic, non-regenerative anemia
Initially may appear to have a normal PCV
NO STRESS LEUKOGRAM
Canine Addisons disease
Hypoadrenocorticism
Diagnosis:
Serum Chemistry
Azotemia
Electrolyte abnormalites:
Hyponatremia, hypochloremia - water loss
Hyperkalemia - aldosterone deficiency and acidosis
Na/K ratio normal >27:1; suspicious <27:1; Supportive <20:1
Hypoglycemia
Acidosis - hypovolemia, diminished renal hydrogen excretion, possible lactic acid production
Hypercalcemia
Hypoalbuminemai - GI loss
Canine Addisons disease
Hypoadrenocorticism
Diagnosis:
Urinalysis
Often <1.030 despite dehydration
Sodium and chloride lossed cannot take place without concurrent loss of water
common findings of azotemia + dehydration + dilute urine
Canine Addisons disease
Hypoadrenocorticism
Diagnosis:
Thoracic Radiographs
microcardia due to profound hypovolemia
Megaesophagus
