Endocrine Flashcards
Cushings - signs
pot belly - increased fat and weakening abdominal wall muscles
polyphagia
lethargy
crusty skin
alopecia
exercise intolerance
muscle wastage
PUPD
HPA Axis
hypothalamus - Corticotropin releasing hormone and vasopressin
anterior pituitary - adrenocorticotropic hormone
adrenals - glucocorticoids
negative feedback loop
cushings - testing
bloods -
stress leukogram
increased ALT and ALP
high cholesterol
urinalysis -
low USG
urine cortisol:creatinine
ACTH stim - high cortisol positive
low dose dexmethasone suppresion test
low dose dexamethasone suppression test
baseline cortisol
give dex
sample again - 4 and 8 hours
differentiate adrenal and pituitary dependent cushings
adrenal - high cortisol both times
pituitary - suppresses at first sample then rises quickly again
don’t use if iatrogenic cushings or stressy dog
cushings - adrenal dependent
adrenal tumour
may have low ACTH because of cortisol negative feedback
adrenal with no tumour may be smaller
large breeds more common
cushings - pituitary dependent
pituitary tumour
produces ACTH without stimulation
high endogenous ACTH
more common in smaller breeds
hyperthyroidism - comorbidities
congestive heart failure - increased GA risk, prolonged sympathetic stimulation
renal disease - may be masked by increased BP from hyperthyroidism then become apparent when treated
diabetes - increased peripheral insulin resistance
hyperthyroidism - treatment
thiamazole - reduces thyroid hormone synthesis
carbimazole - same function as above
diet - low iodine - aim being so they can’t make as much thyroid hormone
surgery - thyroidectomy with various levels of parathyroid preservation (best to keep as much as possible but important not to leave any tumour tissue)
radioactive iodine - gold standard, but can’t go near them for a few days after
hyperthyroidism - treatment monitoring
oral meds -
serum T4 at 2-3 weeks after start of treatment
serum T4, biochem and hematology at weeks 4, 8 and 12 after table
urinalysis and BP ever 3-6 months - for renal disease and diabetes
diet -
serum T4 at 4 weeks - check levels decreasing
check monthly
can take a long time to work
surgery -
2 weeks post surgery
1, 3, 6, 12 months after
radioactive iodine - as for surgery
TSH if signs of hypothyroidism
hypothyroidism - comorbidities
cardiac disease - doesn’t cause but can impact already deficient function
diabetes - immune mediated, associative rather than causative - makes diabetes more difficult to treat
hypoadrenocorticism - treatment may lead to adrenal crisis if existing issue (check for both)
myxodema coma - rare but serious sequelae - comatose, cold, slow heart, low BP, hypoventilation
hypothyroidism - treatment
levothyroxine - synthetic thyroid hormone - tablet or liquid
not with food - decreases drug absorption
hypothyroidism - treatment monitoring
total T4 4-6 hours after medication
monitor for clinical signs
if T4 normal but still showing signs - check circulating TSH
cushings - cats
usually presents as insulin resistant diabetes
treatment not very successful
surgery difficult and risky
(Refer)
cushings - treatment
trilostane - oral - decreases cortisol and aldosterone production (have to get little ones made special for very small patients, can’t break them up)
surgery - adrenalectomy - only if adrenal dependent, not often done and only if unilateral
radiotherapy - macroadenomas only
cushings - monitoring treatment
ACTH stim - pre treatment and then at 10 days, 4 weeks, 12 weeks
then every 3 months
measures 4-6 hours after dosing
Addisons
uncommon in dogs, rare in cats
underproduction of glucocorticoids
predisposed breeds - poodle, portuguese water dog
Iatrogenic addisonian crisis - risk when coming off steroids too fast
Addisons - comorbidities
hypothyroidism - treatment for hypothyroidism can predispose to Addisons
sequelae - addisonian crisis
Addisonian crisis
hypovolemic shock
brady or tachycardia
collapse
depression
hypothermia
rapidly progressing and life threatening
if undiagnosed before go into crisis - probably just die
Addisons - signs
random signs, all the things
hard to spot
Addisonian crisis - treatment
fluids to stabilise shock - until eating, also helps resolve hyperkalemia
IV steroids
glucose CRI - for hypoglycemia
Addisons (non-crisis) - treatment
prednisolone - titre to lowest effective dose, increase at known stress periods
zycortal - monthly injection, complicated to monitor
diabetes mellitus - comorbidities
hypothyroidism - associative
obesity
acromegaly
hypoeradrenocorticism (cushings)
pancreatitis
other inflammatory disorders
any condition that increases peripheral insulin resistance
diabetes mellitus - complications
diabetic neuropathy - glucose build up in nerves, plantigrade stance
UTIs - glucose in urine feeds bacteria
ocular disease - cataracts in dogs, retinal neuropathy in cats - to do with osmotic balance
diabetic ketoacidosis - in uncontrolled cases, life threatening
diabetic ketoacidosis - signs
uncontrolled diabetic
pupd
vomiting
lethargy
anorexia
tachypnoea
acetone breath
dehydration
hypothermia
coma - late stage
diabetic ketoacidosis - testing
urinalysis - glucose, kerones
serum - ketones and glucose
metabolic acidosis
diabetic ketoacidosis - treatment
correct dehydration - fluids
address electrolytes and acid base - phosphate, calcium and magnesium
can give bicarb but usually sorts itself and can cause alkalosis
once sorted all that -
insulin - monitor every 2 hours
identify underlying cause - usually a concurrent disorder (pancreatitis, UTI, cushings, CKD, hepatic lipidosis, cholangiohepatitis)
check medication is actually being given properly
diabetes mellitus - treatment
diet -
control obesity
energy from protein and fat - decrease post prandial glucose increase
can’t use high protein in pancreatitis or CKD
oral hypoglycemics -
cats only
stimulates insulin secretion from pancreas
not very effective, esp over time
good in exotics
velagliflozin -
stops reuptake of urine after filtration
controls signs
may cause diarrhoea - but usually self limiting
risk of UTI from glucose in urine
can still go into ketosis - glucose not going into cells, just being peed out
insulin therapy -
best
caninsulin - pig insulin - injectable by owner, better in dogs than cats
prozinc - human insulin - kept in fridge, not shaken
ovariohysterectomy -
along with insulin therapy
just because diabetes harder to control in entire females
diabetes mellitus - treatment monitoring
owner diary - doses, food, water, demeanor, weight, BCS
blood glucose curves - 12 weeks after treatment start
continuous glucose monitoring
serial fructosamine measurements
