Adrenal gland - Cushing's/Addison's

Question 1

What dermatological changes are seen with hyperadrenocorticism?

Answer 1

Hyperpigmentation
Symmetrical alopecia
Calcinosis cutis
Comeones
Demodicosis
Secondary infections

Question 2

Apart from the general Cushing’s size, how does Cushing’s affect the liver? What about the repro system?

Answer 2

Hepatomegaly (and increased ALP, ALT, cholesterol)
Enlarged vulva/clitoris but anoestrus
Decreased testes size

Question 3

Hyperadrenocorticism leads to an overproduction of cortisol. Where is cortisol produced?

Answer 3

Adrenal cortex

Question 4

What are the two types of Cushing’s? What size of dog is affected

Answer 4

Pituitary dependent (PDH) - 85% cases, small dogs
Adrenal dependent (ADH) - 15% cases, larger dogs

Question 5

Iatrogenic Cushing’s is due to the administration of steroids. Does this cause pituitary or adrenal depedent hyperadrenocorticism?

Answer 5

Adrenal

ADH

Question 6

What are the methods of diagnosing Cushing’s?

Answer 6

Low dose dexamethasone suppression test (best method, but affected by stress)
ACTH stimulation test

Question 7

How can you distinguish between ADH and PDH Cushing’s on low dose dexamethasone stimulation test?

Answer 7

ADH causes slight drop in cortisol then flatlines high

PDH causes sharp drop then increase

Question 8

What may be seen on urinalysis with Cushing’s?

Answer 8

Low USG
Proteinuria
UTI

Question 9

What haematological changes may be seen with Cushing’s?

Answer 9

Stress leukogram

SMILE

Question 10

What are the drug treatment options for Cushing’s?

Answer 10

Trilostane
Mitotane
L-deprenyl
(Can also do surgery/radiotherapy if tumours)

Question 11

How does Cushing’s affect blood pressure?

Answer 11

Causes hypertension - may require treating (atenolol, propranolol)

Question 12

A Scottish terrier presents with signs of Cushing’s. Do you treat with trilostane?

Answer 12

No - no Cushing’s Tx required

Likely to be Scottish Terrier Hepatopathy

Question 13

Hypoadrenocorticism (Addison’s) is less common than Cushing’s. What sex and age dog are predisposed? Which breeds?

Answer 13

Middle aged females

Poodles, Rottweiler, Leonberger, WHW, Great Dane, Portuguese water dog, St Bernard etc

Question 14

What are the clinical signs of Addison’s?

Answer 14

V+, D+ with blood

Lethargy, weakness, PUPD, abdominal pain

Question 15

How can you differ Addisonian crisis from other causes of hypovolaemia?

Answer 15

Hypovolaemia - usually get tachycardia

Addison’s - Bradycardia and hypovolaemia

Question 16

What type of anaemia does Addison’s cause?

Answer 16

Mild non-regenerative anaemia if chronic
Regenerative anaemia (if melaena)

Question 17

What are the symptoms of ADdisonian crisis?

Answer 17

Collapse, syncope, bradycardia, weak pulses

Question 18

Addison’s causes major electrolyte changes.Give examples

Answer 18

Hyper Ca, K
Hypo N
Na: K ratio <27: 1

Question 19

How is Addison’s diagnosed?

Answer 19

Cortisol testing (ACTH, LDDST)
ECG - bradycardia, complete heart block

Question 20

How is Addison’s treated?

Answer 20

Oral steroids - prednisolone, fludrocortisone, DOCP

Question 21

What is atypical Addison’s? What causes it?

Answer 21

Presentation like Addison’s but ACTH and LDDST normal

Due to atypical adrenal metabolism of hormones

Question 22

How is Addisonian crisis treated?

Answer 22

Dextrose
Saline 0.9% NaCl (raise Na slowly)
Calcium gluconate for hyperkalaemia

Question 23

What causes primary Addison’s?

Answer 23

Destruction of >90% of adrenal cortex

Adrenocortolysis - may be immune mediated