Hyperadrenalcortism

Question 1

What are the presenting signs seen in dogs with HAC (hyperadrenocorticism)

Answer 1

POLYPHAGIA, PU/PD, abdominal enlargement (pot-bellied), muscle weakness, SKIN (bilateral truncal alopecia, CALCINOSIS CUTIS, THIN SKIN, bruising, comedones, hyperpigmentation) heat intolerance, panting, lethargy, obesity, reproductive (anestrus, testicular atrophy), neuro (facial paralysis, pseudomyotonia)

Question 2

What are the different types of HAC

Answer 2

Pituitary Dependent HAC
Adrenal dependent HAC
Iatrogenic HAC

Question 3

What is the test of choice for HAC

Answer 3

Low Dose Dexamethasone Suppression Test (LDDS)

Question 4

What are all the tests Available for HAC and some strength/weaknesses for each

Answer 4

Urine Corrisol:Creatinine Ratio - good screening test that you can use when the patient is not sick but has some clinical signs

AtCH stimulates test- Gold standard test for iatrogenic HAC

LDDS - screening test of choice for HAC. Patients MUST have clinical signs of HAC to interpret results, it could potentially help with identifying where the neoplasia is

HDDS - similar to LDDS

Question 5

How do you treat a case of HAC

Answer 5

Surgery (referral for both removing an adrenal or hypophysectomy)

Medical management - 1. Trilostane - blocks the synthesis of adrenal and gonadal steroid hormone (must continue to monitor as adrenal will continue to enlarge.) 2. Mitotane - adrenocorticolytic (destroys adrenal cortex) monitor as you can over treat (cause hypoadrenocortism)

Question 6

What are some hormones secreted from the Pituitary gland

Answer 6

Posterior- ADH and oxytocin
Anterior - ACTH, TSH, growth hormone, and sex hormones

Question 7

What are the zones of the adrenal gland and what does each get stimulated by to produce what

Answer 7

Zona Glomerulosa - stim by Ang II and K, produces mineral corticosteroids

Zona Fasiculata and Reticularis - stim by ACTH to produce glucocorticoids

Medulla- sympathetic nervous system to produce catecholamines

Question 8

What is Pituitary Dependent HAC

Answer 8

Pituitary tumor making ATCH bursts at a chronic length which will cause an excess of systemic cortisol and adrenocortical hyperplasia.

Seen in 80-85% cases, normally a pituitary adenoma, most are small some are big and cause compression on cns

Question 9

What is Adrenal Dependent HAC?

Answer 9

Excessive cortisol secretion caused by an adenoma/carcinoma of the adrenal gland. This is typically unilateral where the unaffected gland will atrophy and there will be suppression of the ATCH negative feedback loop (pituitary independent)

Question 10

What is iatrogenic HAC

Answer 10

A systemic increase of cortisol due to steroids that will suppress ATCH. Hence you will get a bilateral adrenocortical atrophy.

Question 11

What is the human disease name that represents canine HAC

Answer 11

Cushings

Question 12

What are some complications associated with HAC

Answer 12

Hypertension, proteinuria, PTE/ATE, UTI, uroliths, CHF, pancreatitis, DM, joint laxity/ligament tears

Question 13

HAC clinpath findings

Answer 13

CBC - stress leukogram, thrombocytosis
Biochem - ELEVATED ALKP, ALT, CHOLESTEROL, TRIGLYCERIDES mild elevated BA, BG, sodium and decrease in potassium
UA - often hyposthenuria, ELEVATED UPC, see UTI

Question 14

What would a normal vs elevated urine cortisol:creatinine ratio indicate

Answer 14

Normal - most likely doesn’t have HAC
Elevated - might have HAC must do further testing

Question 15

How would you interpret test results of an ATCH stim test

Answer 15

ACTH stim test - take baseline cortisol levels, then inject with synthetic ATCH then after 60-90 mins analyze the results
In normal patients their cortisol levels should rise
In HAC they should have a super high cortisol response
In iatrogenic HAC (or Addisons) they will have a flatline

Question 16

How would you interpret a low dose dexamthasone suppression test

Answer 16

LDDS - attain baseline cortisol, inject dexamethasone, and measure 4 and 8 hours post injection
-Normal patients their cortisol should be suppressed
-In pituitary dependent hyper cortisol you will see no suppression at the 8hr but suppression at the 4 hour
-If you have no suppression at either the 4 or 8 hour you cannot determine if it is pituitary dependent or adrenal dependent (as adrenal will never suppress but 25% of pituitary will also not suppress) so would need further testing

Question 17

What are some advance imaging you can do to differentiate PDH and ADH

Answer 17

Ultrasound - ADH will have one enlarged adrenal gland and one atrophied. VS PDH will have bilateral hyperplasia
CT - can look at adrenal size, invasions of masses, assess for Mets
MRI - detect pituitary adenoma

Question 18

What do you do when your clinical signs suggest hyperadrenocorticism but tests are inconclusive

Answer 18

Wait and retest
Consider ACTH stim test with sex hormone panne.

Question 19

What do you do when you have minimal signs but tests suggest HAC

Answer 19

Hold off on treatment and monitor patient and ensure there were no false positives (like stress induced)

Question 20

What is a major clinical sign in cats that they have hyperAC

Answer 20

Single skin tear this is due to the skin becoming super thin and fragile (can also see comedones, calcanious cutis)

Question 21

If cats are presenting with diabetes and hypertension what should you do

Answer 21

Look for something else other than the diabetes going on. Cats with hyperAC will present as diabetic