Lecture 9 2/18/25 Flashcards
What are the general characteristics of Addison’s?
-adrenocortical insufficiency leads to low aldosterone and low cortisol
-can be life-threatening with adrenal crises
-great pretender; vague, waxing and waning signs that are non-specific and worsen with stress
-auto-immune destruction of adrenal cortex
-both glands abnormal
What are the characteristics of the zona glomerulosa?
-produces mineralocorticoids
-under RAAS regulation
-negligible effect by ACTH from pituitary
What are the characteristics of the zona fasciculata?
-produces glucocorticoids/cortisol
-under HPA regulation
-70% of cortisol under HPA control
What are the steps of the HPAA?
-CRH from the hypothalamus stimulates release of ACTH from pituitary
-ACTH stimulates formation and secretion of cortisol from both adrenal glands
-cortisol has negative feedback on CRH and ACTH
What are the normal functions of cortisol?
-carb, fat, and protein metabolism
-decreases inflammation
-regulates blood pressure
-increases blood glucose
-regulates sleep
-boosts energy
-increases appetite
Which organ is targeted by aldosterone?
kidney
What are the functions of aldosterone at the kidney?
-increases absorption of sodium and water into the bloodstream
-increases excretion of potassium into the urine
-increases excretion of H+ into the urine
How does angiotensin 2 relate to aldosterone?
angiotensin 2 stimulates zona glomerulosa cells to convert cholesterol into aldosterone
How does atrial natriuretic peptide relate to aldosterone?
inhibits adrenal secretion of aldosteron
What is the typical signalment of addison’s in dogs?
-young to middle aged
-mostly female
What is the typical signalment of addison’s in cats?
-young to old
-no gender predisposition
-mostly DLH/DSH
Which dog breeds have a predisposition for developing Addison’s?
-standard/mini poodle
-westies
-great danes
-bearded collies
-portuguese water dogs
-rottweilers
-wheaten terriers
What are the common presenting signs of addison’s?
-lethargy
-exercise intolerance
-recurrent bouts of GI signs
-GI ulcers
-anorexia/hyporexia
-low BCS
-progressive weight loss
-PUPD
-dehydration
-acute circulatory collapse
-prone to illness when stressed
-bradycardia
-weakness
-tremors/shaking
-seizures
-hypotension
Which signs are most common in Addison’s?
lethargy and vomiting
What are the abnormalities seen on chem/lytes in Addison’s patients?
-elevated K+
-elevated H+
-decreased Na+
-decreased Cl-
-azotemia
-mild acidosis
-hypoglycemia
-hypocholesterolemia
-hypercalcemia
-hypoalbuminemia
-elevated liver values
What are the abnormalities seen on CBC in Addison’s patients?
-normocytic, normochromic nonregenerative anemia
-thrombocytosis
-lymphocytosis
-eosinophilia
-lack of stress leukogram
What is the USG seen on UA in Addison’s patients?
< 1.030
What are the main findings on blood work that indicate Addison’s?
-may have normal blood work or any abnormalities
-low Na and high K
-hypercalcemia
-hypoglycemia
-azotemia
How does the arrhythmia change based on severity of hyperkalemia?
-lower levels of hyperkalemia can lead to bradycardia
-higher levels of hyperkalemia can lead to v-fib or asystole
What are the radiographic findings seen in Addison’s?
-microcardia
-underfilled vasculature
-megaesophagus
-possible pneumonia
What are potential findings on abdominal ultrasound in Addison’s?
-small to normal adrenals
-abnormal or large adrenals; complicated by infiltrative disease
What are distinctive red flags for Addison’s?
-hypotension + bradycardia + poor pulses
-azotemia + dehydration + hyponatremia
-lymphocytosis +/- low Na/K ratio when sick
Which diseases can Addison’s disease look like?
-kidney failure
-protein losing enteropathy
-chronic enteropathy
-cancer
-epilepsy or brain tumor
-liver failure
-primary esophageal disease or GERD
-acute and/or chronic GI disease
-GI bleeding
-myopathies/neuropathies
-endocrinopathies
-toxins
