adrenal disorders

Question 1

hyperadrenocorticism in dogs

Answer 1

85% PDHAC- pars distalis tumour
15% ADHAC- adenoma/carcinoma

iatrogenic

Question 2

hyperadrenocorticism C/S

Answer 2

older dogs
PU/PD (ADH inhibition, increased GFR), alopecia, lg abd, hepatomegaly, PP, weakness

Question 3

hyperadrenocorticism dx

Answer 3

CBC- stress leukogram, high RBC
chem- high ALP, lipid, ALT
low USG, proteinuria
high BP, silent UTI
abd U/S- differentiate type (adrenals should be <7.5mm), GB mucocele
rads

Question 4

differentials for ALP higher than ALT

Answer 4

DM, cushings, cholangitis, cholestasis, gallstone, steroids, phenobarb, neoplasia

Question 5

HAC screening tests

Answer 5

Question 6

ACTH stim

Answer 6

specific but not sensitive
doesnt differentiate

Question 7

LDDST

Answer 7

very sensitive, less specific
look for little/no suppression after 0.015mg/kg dexamethasone
dx if 8h is over ref, if suppression at 4h-> PDHAC

Question 8

HAC differentiating tests

Answer 8

LDDST, abd U/S
HDDST (0.1mg/kg)- if any suppression= PDHAC

Question 9

PDHAC tx

Answer 9

hypophysectomy
trilostane (inhibits cortisol production)- 1mg/kg q12, recheck in 7-10d and increase if >250 w no change in C/S, stop if <70

mitotane- cytotoxic to adrenal cortex 30-50mg/kg/d 5-8d, maintain on 50mg/kg/wk 2-3X per wk

Question 10

ADHAC tx

Answer 10

sx- adrenalectomy
mitotane to destroy tumour

Question 11

HAC complications

Answer 11

hypertension
bladder stones (calcium oxalate)
UTIs
vascular accidents, seizures
neurologic signs
DM
hypercoagulability, PTE
mucocele

Question 12

feline HAC

Answer 12

pituitary tumours
PU/PD, PP, thin skin
insulin resistant DM
dx- HDDST
tx- radiation, adrenalectomy

Question 13

hypoadrenocorticism

Answer 13

loss of 85% adrenal reserve
typical- glucocorticoid/mineralocorticoid deficiency
atypical- just glucocorticoid

causes: immune mediated adrenalitis, iatrogenic

rare- std poodle, PWD, duck toller

Question 14

hypoadrenocorticism C/S

Answer 14

vague, intermittent
anorexia, v+, lethargy, d+, weight loss, weakness, shivering
PU/PD, melena

Question 15

hypoadrenocorticism dx

Answer 15

CBC- lack of stress leukogram
chem- hyperkalemia, azotemia, hyponatremia, low USG
ECG- bradycardia, hyperkalemia
check baseline cortisol, if <55 do ACTH stim

Question 16

acute addisons tx

Answer 16

10ml/kg bolus to effect, balanced electrolyte
dexamethasone- 0.1-0.2mg/kg
calcium gluconate, dextrose if hyperkalemic

Question 17

at home tx for addisons

Answer 17

DOCP- mineralocorticoid only, expensive but easier q25d
fludrocortisone- some glucocorticoid activity, difficult to dose in lg dogs

glucocorticoids (pred)- start at 0.5mg/kg/d and taper down (especially if DOCP)

Question 18

addisons monitoring

Answer 18

typical-Na/K ratio 1m
q3-6m after that

atypical- pred only, monitor C/S only