Endocrinology - Cushings 1

Question 1

What is Cushing’s?

Answer 1

Hyperadrenocorticism

Question 2

What does HAC mean?

Answer 2

Hyperadrenocorticism

Question 3

What does PDH mean?

Answer 3

pituitary-dependent hyperadrenocorticism

Question 4

What does ADH mean?

Answer 4

adrenal dependent hyperadrenocorticism

Question 5

What is an FAT?

Answer 5

Functional adrenal tumor

Question 6

What is LDDST?

Answer 6

Low dose dexamethasone suppresion test

Question 7

What is HDDST?

Answer 7

high dose dexamethasone suppression test

Question 8

What is HPA?

Answer 8

hypothalamic-pituitary-adrenal axis

Question 9

What is the catabolic role of glucocorticoids?

Answer 9

Accelerate protein break down and inhibit DNA, RNA, and protein synthesis

Question 10

What roles do glucocorticoids have in metabolism?

Answer 10

Increase gluconeogenesis, increase fatty acid metabolism, stimulate muscle catabolism, prevent muscle and fat uptake of glucose, oppose the actions of insulin, and increase glycogen storacge

Question 11

How do glucocorticoids act on the CNS?

Answer 11

Appetite stimulation

Question 12

How do glucocorticoids act on the vasculature?

Answer 12

maintain normal BP and constrict the vasculature

Question 13

How do glucocorticoids act on the GI tract?

Answer 13

They maintain normal perfusion and motility

Question 14

How do glucocorticoids act on the inflammatory/immune systems?

Answer 14

They keep neutrophils in the blood vessels and inhibit their function, inhibit inflammation, and inhibit wound healing

Question 15

What renal effects do glucocorticoids have?

Answer 15

Inhibit ADH action at the kidney (nephrogenic diabetes insipidus) and PU/PD

Question 16

What is hyperadrenocorticism?

Answer 16

chronic excess of circulating glucocorticoids

Question 17

What are the ‘3 flavors’ of Cushing’s?

Answer 17

Pituitary depended hyperadrenocorticism, functional adrenal tumors, and iatrogenic disease

Question 18

What causes PDH?

Answer 18

A pituitary tumor - microadenomas or macroadenomas

Question 19

What is another term for functional adrenal tumors?

Answer 19

adrenal dependent hyperadrenocorticism

Question 20

What can cause iatrogenic Cushing’s?

Answer 20

exogenous glucocorticoid administration

Question 21

What is the signalment for Cushing’s?

Answer 21

Middle to older aged dogs - poodles, boxers, and dachschunds are overrepresented

Question 22

What size dog typically gets PDH?

Answer 22

Small breed dogs

Question 23

What are the high risk breeds for ADH?

Answer 23

GSD, Daschund and Labrador retriever

Question 24

What are the common signs associated with Cushing’s?

Answer 24

THEY ARE SLOW ONSET - Polydipsia, polyuria, polyphagia, pot-bellied, hair loss, skin infections, panting, muscle weakness, and lethargy

Question 25

What are the not so common but common signs associated with Cushing's disease?

Answer 25

Various cutaneous changes, myotonia, and CNS signs

Question 26

True or False: Dogs with Cushing's are not generally sick

Answer 26

TRUE

Question 27

What conformational changes are associated with Cushing's?

Answer 27

hepatomegaly, abdominal muscle weakness, increased intra-abdominal fat, and muscle atrophy which results in pendulous abdomen

Question 28

What cutaneous changes are associated with Cushing's?

Answer 28

Symmetrical alopecia, comedones, hyperpigmentation, and scaling

Question 29

What signs are associated with pituitary macroadenoma syndrome?

Answer 29

Lethargy, listlessness/dullness, aimless wandering, head pressing, behavioral alterations, seizures, circling, and ataxia

Question 30

How do you diagnose Cushing's?

Answer 30

History, PE findings, clinical pathology data, and adrenal function tests

Question 31

What will you find on a CBC in a patient with Cushing's?

Answer 31

Stress leukogram, thrombocytosis, and hemoconcentration

Question 32

There is an acronym to remember what a stress leukogram looks like. It is SMILED. What does it stand for?

Answer 32

Segs and Monocytes Increase, Lymphs and Eosinophils Decrease

Question 33

What will you find on a chemistry panel in a patient with Cushing's?

Answer 33

elevated ALP, mild ALT elevation, increases in plasma glucose, hypercholesterolemia, and hypertriglyceridemia

Question 34

What will you find on a UA in patients with Cushing's?

Answer 34

Dilute urine, proteinuria, and potentially a UTI

Question 35

Is thyroid testing a Cushingoid dog reliable?

Answer 35

no - hyperadrenocorticism causes euthyroid sick syndrome

Question 36

What will you find on radiographs in Cushing's patients?

Answer 36

Hepatomegaly, good abdominal detail due to fat, pot-bellied appearance, and urinary bladder distension

Question 37

What are some common complications associated with Cushing's?

Answer 37

Hypertension, hypercoagulability (thromboembolism), calcium oxalate urinary stones, and infections

Question 38

What infections can be complications of Cushing's?

Answer 38

UTI, pyoderma, Malassezia, and dermatophytosis

Question 39

How do you test for hyperadrenocorticism?

Answer 39

Screening tests to confirm, or localizing tests to determine origin

Question 40

What screening tests can be done to confirm Cushing's?

Answer 40

Urine cortisol-creatine ration, low-dose dexamethasone suppresion test, and ACTH stimulation test

Question 41

True or False: You should test a dog for HAC that is concurrently ill with an acute illness

Answer 41

False - you should not because you will get a false positive result

Question 42

Urine cortisol:creatinine test is a reasonable ____ ____ test.

Answer 42

rule out

Question 43

If a urine cortisol:creatinine test is normal, how likely is HAC?

Answer 43

UNLIKELY

Question 44

When is it best to collect a sample for a urine cortisol:creatinine test?

Answer 44

collect it at home

Question 45

What is the ACTH stimulation test?

Answer 45

Administration of a supraphysiologic dose of ACTH which causes the adrenals to maximally secrete cortisol

Question 46

What does the ACTH stimulation test gauge?

Answer 46

The adrenal reserve of corticoids

Question 47

If a dog has PDH, what will the result of the ACTH stimulation test be?

Answer 47

an excessive response post administration

Question 48

Dogs with FAT will show _____ responses to ACTH.

Answer 48

variable

Question 49

What are the pros to the ACTH stimulation test?

Answer 49

Safe, simple, quick, and specific

Question 50

What are the cons to the ACTH stimulation test?

Answer 50

Less sensitive than the LDDST, cannot tell PDH vs. FAT apart, and cost of cosyntropin

Question 51

When is the ACTH stimulation test recommended?

Answer 51

In dogs with concurrent non-adrenal illness

Question 52

What is the ACTH stimulation test the preferred diagnostic for?

Answer 52

Iatrogenic HAC

Question 53

What does the LDDST test for?

Answer 53

decreased HPA axis sensitivity to negative feedback from glucocorticoids

Question 54

True or False: LDDST is the single best test to screen for HAC

Answer 54

TRUE

Question 55

How is a LDDST done?

Answer 55

Measure baseline cortisol, give 0.01 mg/kg dex IV, and then measure cortisol at 4-8 hours post administration

Question 56

How do you interpret the LDDST results?

Answer 56

First look at the 8 hour result, then look at the four hour result

Question 57

If your result is greater than 1.4 micrograms/dl at 8 hours, what does that indicate?

Answer 57

You have HAC

Question 58

If your result is less than 1.4 micrograms/dl at 8 hours, what does that indicate?

Answer 58

You do not have HAC - you are done

Question 59

If there is suppresion of LDDST at 4 hours, what does that indicate?

Answer 59

There is PDH

Question 60

If there is no suppression of LDDST at 4 hours, what does that mean?

Answer 60

You cannot differentiate between PDH from FAT

Question 61

What are the pros to LDDST?

Answer 61

High sensitivity, differentiates PDH from AT in 40% of dogs with HAC, safe, and inexpensive

Question 62

What are the cons to LDDST?

Answer 62

Less specific than ACTH stimulation and takes 8 hours