Diseases of the Pituitary Gland (and PU/PD) Flashcards
what are the diabetogenic hormones?
glucagon
growth hormone
cortisol
epinephrine
progesterone- gestational
what is acromegaly usually from in dogss?
progesterone causing growth hormone release from the pituitary and mammary glands
how can you test for acromegaly?
growth hormone levels
IGF-1 levels
CT or MRI
what is polydipsia?
> 100 ml/kg/day
what are the causes of primary polyuria?
central diabetes insipidus
primary nephrogenic diabetes insipidus
secondary nephrogenic diabetes insipidus
what is central diabetes insipidus?
lack of production of ADH by the hypothalamus, or release by posterior pituitary
what can cause ADH interference?
hyperadrenocorticism
E. coli pyometra/UTI
how can you measure GFR?
creatinine clearance
nuclear scintigraphy
iohexol clearance
when should you conclude a modified water deprivation test?
concentrated urinee
patient becomes dehydrated/azotemic/ill
serum osmolality > 320 mOsm/kg
3-5% body weight lost
what can cause insulin resistance?
estrus or pregnancy
infection
hyperthyroidism
hyperadrenocorticism
acromegaly
poor absorption of insulin
what is acromegaly usually from in cats?
growth hormone secreting pituitary tumor
what endogenous things can cause progesterone leading to growth hormone release in dogs?
diestrus
gestation
how can you diagnose acromegaly?
clinical signs
history of progesterone use
insulin-resistant diabetes mellitus
tests
how can you treat acromegaly in cats?
megavoltage radiation therapy
surgical hypophysectomy
lots of insulin
octreotide acetate, pasireotide
what is polyuria?
> 50 mL/kg/day
what can cause primary polyuria?
central diabetes insipidus
primary nephrogenic diabetes insipidus
secondary nephrogenic diabetes insipidus
what can lead to failure of the tubules to respond to ADH?
osmotic diuresis
ADH interference
loss of medullary concentration gradient
conditions affecting aquaporin 2
what is the “standard” workup for pu/pd?
cbc
chem
ua
urine culture
T4
testing hyperadrenocorticism
how can you measure GFR?
creatinine clearance
nuclear scintigraphy
iohexol clearance
what type of water deprivation test can you perform?
gradual water deprivation test
what result in exogenous ADH test is consistent with central diabetes insipidus?
dramatic reduction in water intake and increase in urine specific gravity
what are the results in the urine is not concentrated after an exogenous ADH test?
nephrogenic diabetes insipidus
medullary washout
can you cure central diabetes insipidus?
no- free access to water at all times
what can you give for central diabetes insipidus?
synthetic ADH: desmopressin
how do animals get primary nephrogenic diabetes insipidus?
congenital
how can you treat primary nephrogenic diabetes insipidus?
thiazide diuretics: increase NaCl excretion, results ECV depletion, inhibits thirst center
low salt, low protein diet
