2/4 Adrenal Glands: Hyperadrenocorticism COMPLETE***

Question 1

State another name used for Hyperadrenocorticism

Answer 1

cushings disease

Question 2

What is Hyperadrenocorticism characterised by?
- What actually causes the clinical signs seen?

Answer 2

excessive production of steroid hormones from the adrenal cortex

the abnormal circulating concentrations of steroid hormones

Question 3

Hyperadrenocorticism: Which species is this commonly seen in?
- Which species is it rarely seen in?

Answer 3

dogs

cats

Question 4

Hyperadrenocorticism: Which 2 broad categories can it be divided into?
- what does the second one mean?

Answer 4

spontaneous or iatrogenic

it means we caused it

Question 5

Hyperadrenocorticism: Spontaneous
- Name the 2 types of Spontaneous hyperadrenocorticism

Answer 5

pituitary dependent
adrenal dependent

Question 6

Hyperadrenocorticism: What happens in Pituitary dependent Hyperadrenocorticism? 2

Answer 6

a mico adenoma or macro adenoma arises from the pars distalis or pars intermedia
this leads to failure of normal negative feedback mechanisms

Question 7

Hyperadrenocorticism: What happens in Adrenal Dependent hyperadrenocorticism? 2

Answer 7

you get unilateral enlargement of an adrenal gland
this causes atrophy of the collateral adrenal gland

Question 8

Hyperadrenocorticism: Give the Signalment 2

Answer 8

pituitary dependent is often seen in dogs 7-9
adrenal dependent is often seen in dogs over 11

Question 9

Hyperadrenocorticism: What causes Bilateral Symmetrical Alopecia?
- What about thin skin?
- What about reduced skin elasticity?

Answer 9

steroids have an inhibitory effect on anagen phase

due to loss of subcutaneous fat

due to protein breakdown

Question 9

Hyperadrenocorticism: State all possible clinical signs in order of most commonly seen to least common 8

Answer 9

bilateral symmetrical alopecia
thin skin
reduced elasticity of skill
polyuria and polydipsia
abdominal enlargement
polyphagia
hepatomegaly
slow wound healing

Question 10

Hyperadrenocorticism: What causes Polyurea and Polydipsia? 2

Answer 10

due to increased GFR
and cortisol antagonising ADH

Question 11

Hyperadrenocorticism: What causes the Pot bellied appearance? 3

Answer 11

due to redistribution of fat into the abdomen
hepatic enlargement
wasting and weakening of abdominal muscles

Question 12

Hyperadrenocorticism: Why do you get Slow wound healing?

Answer 12

because steroids inhibit fibroblast proliferation and collagen synthesis

Question 13

Hyperadrenocorticism: What causes the Polyphagia?

Answer 13

this is a direct effect of glucocorticoids

Question 14

Hyperadrenocorticism: Diagnostics
- Why can Diagnosing this disorder be difficult?

Answer 14

because anything that causes stress can lead to an increase in cortisol

Question 14

Hyperadrenocorticism: Diagnosis
- State the order of steps you could take in diagnosis (for non-specific tests)

Answer 14

review history
review clinical examination
blood biochemistry
complete blood count
urinalysis
abdominal and thoracic radiographs
ultrasound

Question 15

Hyperadrenocorticism: Why would you review history and clinical exam?

Answer 15

to determine whether or not they are suspicious of hyperadrenocorticism

Question 16

Hyperadrenocorticism: What would you expect to see on a Blood Biochemistry? 3

Answer 16

elevated ALP
elevated cholesterol
elevated blood glucose

Question 17

Hyperadrenocorticism: What would you expect to see on Complete blood count and why? 2

Answer 17

neutrophilic as the neutrophils have been released from the marginating pool
lymphopenia as steroids suppress the immune system

Question 18

Hyperadrenocorticism: What would you expect to see on Urinalysis? 2

Answer 18

a low USG of less than 1.015
evidence of a urinary tract infection

Question 19

Hyperadrenocorticism: What could you see on an Abdominal radiograph? 5

Answer 19

potbellied appearance
hepatomegaly
calcinosi cutis
adrenal enlargement
distended bladder

Question 20

Hyperadrenocorticism: What might you see on a Thoracic radiograph?

Answer 20

tracheal and bronchial wall mineralisation

Question 21

Hyperadrenocorticism: What might you see on an Ultrasound of the adrenals?

Answer 21

one adrenal larger than the other

Question 22

Hyperadrenocorticism: What does High Sensitivity mean for a test? 3

Answer 22

it is a screening test
it is highly sensitive so will give some false positives
a negative is definitely negative

Question 23

Hyperadrenocorticism: What does High Specificity mean on a test? 3

Answer 23

it can be used to rule in a disease
a positive result is definitely positive
may get some false negatives

Question 24

Hyperadrenocorticism: State some Disease specific diagnostic tests for diagnosis of Hyperadrenocorticism 3

Answer 24

urinary cortisol: creatinine ratio
ACTH stimulation
LDDS test

Question 25

Hyperadrenocorticism: Urinary cortisol: creatinine ratio
- Describe sensitivity/specificity
- Hence, what type of test is this?
- What result would indicate the disease?

Answer 25

high sensitivity
low specificity

a screening test

a high ratio

Question 26

Hyperadrenocorticism: ACTH Stimulation
- Describe the process for carrying out this test 4
- What would a positive result look like and why?
- Describe the sensitivity and specificity of this test

Answer 26

starve overnight
test plasma cortisol at time 0
inject synthetic ACTH
collect a sample in 60 minutes

over 600 post stimulation
dogs with spontaneous hyperadrenocorticism have an exaggerated response to exogenous ACTH

high specificity low sensitivity

Question 27

Hyperadrenocorticism: LDDS Test
- Describe the Procedure 4
- Describe what happens in a HAC dog 2

Answer 27

starve overnight
measure plasma cortisol
inject dexmethasone
measure cortisol at 3 and 8 hours

the exogenous glucocorticoid should reduce ACTH secretion by negative feedback
so the cortisol measured in HAC dogs will remain elevated

Question 28

Hyperadrenocorticism: After diagnosing HAC, you need to differentiate between Pituitary Dependent and Adrenal dependent.
- How can you do this?
- What will you see? 2

Answer 28

adrenal imaging

for pituitary dependent both adrenals will be symmetrically enlarged
for adrenal dependent one adrenal will be enlarged and one will be atrophied

Question 29

Hyperadrenocorticism: Treatment
- What can you give to treat this?
- What surgical route is there and why is this less preferable?

Answer 29

trilostane

adrenalectomy or hypophysectomy
less preferable as animal will require steroid therapy for the rest of its life

Question 30

Hyperadrenocorticism: Cats
- Although Rare, if cats get HAC, is it normally Pituitary dependent or Adrenal Dependent?

Answer 30

pituitary dependent