Hyperadrenocorticism

Question 1

what are the clinical signs associated with hyperadrenocorticism (cushings)?

Answer 1

• hepatomegaly
• cutaneous manifestations including hyperpigementation, thin skin, rat tail, comedones, bruising calcinosis cutis
• panting
• muscle weakness
• hypertension
• hypercoagulability

THE 4 P’s!

1. PU/PD
2. Polyphagia
3. Panting
4. Pot belly

Question 2

list the common laboratory findings associated with hyperadrenocorticism

Answer 2

increased ALP in 90% of cases, proteinuria on urinalysis

Question 3

what are the 3 screening tests for cushings?

Answer 3

Low-dose dexmathasone
ACTH stim test
Urine cortisol:creatinine ratio

Question 4

LDDST summary

Answer 4

1. pre cortisol sample
2. give dex inj and measure cortisol at 4 and 8 hrs post
3. the 8 hour sample determines if cushings is present with 95% sensitivity but specificity is low

Question 5

how do you interpret LDDST results?

Answer 5

observe the 8 hour cortisol:
- if not suppressed (increased) then its HAC
- if suppressed not HAC

Pituitary dependent cushings:
- suppressed at 4 hour
- 4 and 8hour <50% of baseline

Question 6

ACTH Stim summary

Answer 6

1. pre-cortisol blood sample
2. inject ACTH
3. cortisol sample 1 hour later
4. elevated if HAC present with 85% specificity and sensitivity

Question 7

ACTH Stim test interpretation

Answer 7

PDH dog and ADH dog will have exaggerated post-cortisol

Iatrogenic HAC dog will have atrophied adrenal glands with no cortisol production (may test like addisons but looks like cushings)

Question 8

UCCR

Answer 8

collect urine at home and then measure cortisol and creatinine in urine
- would have HAC dogs have excess urinary cortisol excretion
- sensitivity is 95% but specificity is poor

Question 9

if other diseases are present what test should you use for cushings?

Answer 9

ACTH stim, avoid LDDST bc of false positives esp with diabetic dogs

Question 10

what should you do if no suppression at 4 hour nor relative suppression at 4 or 8 hour to differentiate between PDH and ADH?

Answer 10

adrenal imaging: AUS
HDDST, eATCH, CT/MRI

Question 11

treatment for cushings

Answer 11

both stop cortisol synthesis

Trilostane: reversible inhibitor of 3 - beta- hydroxysteroid

Mitotane: destroys zonae fasciculata and reticularis

check after 2 wks, make sure they’re not hypoadreno

Question 12

insulin resistance in cats clinical signs

Answer 12

PU/PD
abdominal enlargement
polyphagia
skin atrophy- thin and tears
muscle wasting

Question 13

insulin resistance lab findings in cats

Answer 13

diabetes mellitus (80%)
hyperglycemia
hypercholesterolemia
glucosuria
minimally concentrated USG

Question 14

Tx of insulin resistances/ hyperadrenocorticism in cats

Answer 14

trilostane, surgery, irradiation