Tests For Endocrine Disease Flashcards
(26 cards)
What is the best screening test for Cushings?
Low dose dexamethasone suppression test
How can you differentiate between pituitary dependent and adrenal dependent hyperadrenocorticism with the dexamethasone suppression test?
Pituitary dependent - ACTH will not be suppressed
Adrenal dependent - ACT will be suppressed
What test can be used to monitor treatment for hyperadrenocorticism?
ACTH stimulation test
What is the best test to rule out hyperadrenocorticism in a work up of PU/PD?
Urine cortisol creatinine ratio
What test is best for determining the origin of the disease?
ACTH assay
- ACTH high - pituitary mediated
- ACTH low - adrenal mediated
When should you perform a high dose dexamethasone suppression test?
When you suspect an adrenal tumour
How can you differentiate between primary, atypical and secondary addisons?
Primary - low cortisol, high ACTH, electrolyte abnormalities
Atypical - low cortisol but normal electrolytes
Secondary - low ACTH, low cortisol, electrolyte abnormalities
How can you diagnose Addisons?
A single cortisol measurement
- below 55
What are the common clinical signs of diabetes mellitus?
PU PD
Polyphagia
Weight loss
What haematological / biochemical / urinalysis abnormalities will you see in diabetes mellitus?
Hyperglycaemia
Increased ALP ALT
Hypetriglyceridaemia l
Ketonuria
Glucosuria
Active sediment
Low USG
How can you diagnose diabetes mellitus?
Clinical signs
Persistent fasting hyperglycaemia
Glucosuria
How does diabetic ketoacidosis present?
Vomiting Depression Dehydration Weakness Tachypnoea
How can you diagnose diabetic ketoacidosis?
Ketonuria
Azotaemia
Acidosis
What electrolytes are lost in the urine due to acidosis in ketoacidosis?
K+ and phosphate
Supplement with fluid therapy
How can you diagnose canine hypothyroidism?
Low total T4 = definitive
Ddx sick euthyroid syndrome
- differentiate using free T4 - free T4 will be normal in dogs with sick euthyroid syndrome
- can also use a TSH assay - TSH will be high in hypothyroid dogs
Low T4 and high TSH = diagnosis of hypothyroidism
TgAAs
Thyroid function tests
What abnormalities will you see on the essential database in hyperthyroidism?
Mild to moderate erythrocytosis and macrocytosis Heinz bodies Leukocytosis Increased ALP, ALT, AST Azotaemia Hyperkalaemia Reduce fructosamine
What common endocrinopathy is seen in combination with feline hyperthyroidism?
Diabetes mellitus
What gives you the most definitive diagnosis of feline hyperthyroidism?
Total T4 elevated
What test is more sensitive in diagnosing early feline hyperthyroidism?
Free T4
What is central DI?
Brain does not release ADH
What is primary DI?
Kidney doesn’t respond to ADH
What is secondary DI?
Kidney doesn’t respond to ADH due to other disease
- renal failure, hyperadrenocorticism, pyo, hypercalcaemia, hyperthyroidism, pyelonephritis, hypoadrenocorticism, liver failure, hypokalaemia, acromegaly
How can you define polydypsia?
Drinking more than 100 ml/kg/day
How can you work up PU/PD?
History - rule out iatrogenic - drugs
Physical - pyo/ renal diseas
Haematology - pyo / pyelonephritis
Biochemistry-hypercalcaemia, hyponatraemia, renal disease, diabetes
Bile acids - liver disease
Total T4 - hyperthyroidism
Urinalysis - diabetes, fanconis, renal glucosuria
Urine creatinine cortisol ratio - hyperadrenocorticism
Water deprivation test - last step
Response to exogenous ADH (central DI)
