Adrenal Diseases

Question 1

What gland produces ACTH?

Answer 1

The anterior pituitary

Question 2

What gland produces cortisol?

Answer 2

The adrenal gland

Question 3

On what gland does ACTH act?

Answer 3

The adrenal gland

Question 4

Canine hyperadrenocorticism CS

Answer 4

7-12 years old
PU/PD
Polyphagia
Pendulous abdomen
Panting
Hepatomegaly
Muscle weakness
Lethragy/Lameness
Endocrine alopecia
Pyoderma/Demodex
Calcinosis cutis

Question 5

Canine Hyperadrenocorticism lab abnormalities

Answer 5

Stress leukogram: lymphopenia, neutrophilia, monocytosis
Increased ALP
Hypercholesterolemia
Hyperglycemia
USG < 1.020
Proteinuria

Question 6

Canine hyperadrenocorticism pathogenesis

Answer 6

85%: pituitary dependent disease: production of excess ACTH, bilateral adrenocortical hyperplasia
15%: adrenal tumors: unregulated production of cortisol: unilateral adrenal enlargement
Or Iatrogenic: chronic steroid use, atrophy of adrenal

Question 7

How do you differentiate between pituitary dependent and adrenocortical tumor?

Answer 7

High dose dexamthasone suppression test
Endogenous ACTH

Question 8

What happens to the urine cortisol: creatinine ratio with hyperadrenocorticism?

Answer 8

It will be increased
Cortisol excretion increases as blood cortisol conc increases, but creatinine is excreted at a constant rate

Question 9

Low Dose Dexamethason Suppression Test

Answer 9

Dex is a proxy for cortisol
Inhibits CRH/ACTH/Cortisol

Cortisol should be decreased in healthy animal

Question 10

In a dog with Hyperadrenocorticism the LDDST should result in ___?

Answer 10

No change in cortisol

Question 11

Can an adrenal tumor be suppressed with dex?

Answer 11

No
Adrenal tumors never suppress

Question 12

LDDST interpretation

Answer 12

If the 8 hr cortisol is NOT suppressed: Cushings
If the 8hr cortisol is NOT suppressed but the 4 hr is: PDH
Lack of suppression: PDH or ADH

Question 13

In a healthy animal, ACTH stim test should result in what?

Answer 13

A mild increased in cortisol

Question 14

ACTH Stimulation Test protocol

Answer 14

ACTH stimulates production of cortisol
Draw base line blood
Administer ACTH
Redraw 1-2 hr later
Measure cortisol

Question 15

With iatrogenic Cushings, the ACTH stim test should result in what?

Answer 15

No change in cortisol
The gland is too atrophied to produce

Question 16

ACTH interpretation

Answer 16

Mild increase: normal
Exaggerated increase: Cushing’s
No Increase: Iatrogenic Cushing’s

Question 17

A dog with Cushing’s has a low endogenous ACTH concentration. This is most consistent with what type?

Answer 17

Adrenal dependent hyperadrenocorticism

Question 18

A dog with Cushing’s has a high endogenous ACTH concentration. This is consistent with what type?

Answer 18

Pituitary dependent hyperadrenocorticism

Question 19

A dog with Cushing’s suppresses with a HDDST. This is consistent with what?

Answer 19

A pituitary dependent hyperadrenocorticism

Question 20

A dog with Cushing’s does not suppress with a HDDST. This is most consistent with what?

Answer 20

Hyperadrenocorticism but can’t tell what type.

Question 21

Equine Cushing’s Disease/Pituitary Pars Intermedia Dysfunction (PPID)

Answer 21

Most common equine endocrinopathy
CS:
Hirsutism/poor hair coat
Laminitis
Lethargy
PU/PD
muscle wasting
Increased appetite
Skin infections

Question 22

Equine Cushing’s lab abnormalities

Answer 22

Stress leukogram
anemia
hyperglycemia
hyperlipidemia
increased liver enzymes
glucosuria

Question 23

Feline Hyperadrenocorticism CS

Answer 23

Uncontrolled diabetes
PU/PD
Polyphagia
Weight loss
Lethargy
Weakness
Dermatopathies

Question 24

Feline Hyperadrenocorticism lab abnormalities

Answer 24

Stress leukogram
lack of consistent abnormalities

Question 25

Feline hyperadrenocorticism pathogenesis

Answer 25

80% =PDH 20% = ADH

Question 26

Feline hyperadrenocorticism diagnosis

Answer 26

Urine cortisol: creatinine LDDST ACTH stim not recommended

Question 27

Hypoadrenocorticism

Answer 27

Addison's disease Decreased glucocorticoid (cortisol) Decreased mineralocorticoid (aldosterone)

Question 28

What normally stimulates cortisol production

Answer 28

ACTH

Question 29

What normally stimulates aldosterone production?

Answer 29

Reduced renal blood flow (RAAS) Hypotension (carotid artery barorecetors) Increased potassium

Question 30

Canine hypoadrenocorticism CS

Answer 30

4-5 year old females > males vague clinical signs intermittent illness ADDISONIAN CRISIS abd pain/shaking lethargy/anorexia V/D, polyuria

Question 31

Canine hypoadrenocorticism lab abnormalities

Answer 31

Lack of stress leukogram in an ill dog normocytic, normochromic anemia Electrolyte abnormalities from decreased aldosterone -Hyponatremia -hypochloremia -hyperkalemia -Sodium: potassium <27:1 Prerenal azotemia USG 1.015-1.030 (should be more concentrated)-can mimic renal failure Hypercalcemia Hyperalbuminemia Hypoglycemia Hypocholesterolemia

Question 32

Primary adrenocortical failure pathogenesis

Answer 32

most common cause of hypoadrenocorticism Destruction of the adrenal cortex (immunemediated, neoplasia, infarct, idiopathic)

Question 33

Secondary adrenal insufficiency pathogenesis

Answer 33

Reduced ACTH from pituitary

Question 34

Idiopathic hypoadrenocorticism pathogenesis

Answer 34

Abrupt discontinuation of steroids (atrophied adrenals)

Question 35

Where is aldosterone produced?

Answer 35

Zona glomerulosa of the adrenals

Question 36

Where is cortisol produced?

Answer 36

Zona fasciculata of adrenals

Question 37

In a dog with Addison's: ACTH stimulation causes what?

Answer 37

No response

Question 38

Canine hypoadrenocorticism diagnosis

Answer 38

ACTH stim test (low cortisol post ACTH)

Question 39

What is the most common cause of hypoadrenocorticism in horses?

Answer 39

Discontinuation of chronic steroid use

Question 40

Is hypoadrenocorticism common in cats and horses?

Answer 40

No