Polydipsia and Polyuria
hyperadrenocorticism attacks where so can't bind
attack renal area and so ADH can't bind so not concentrated
when should you not do the water deprivation test
azotemic (kidney failure/disease), dehydrated or hypercalcemic
small animals usually have Pu as the primary problem with...
compensatory polydipsia
increased water consumption causes what
compensatory polyuria
what are some disorders produce P&P
diabetes insipidus, diabetes mellitus, hyperadrenocorticism, hypercalcemia, hyperthyroidism, liver failure, medullary washout, pyometra, pseudopsychogenic polydipsia, renal disease, iatrogenic
what is an insulin deficiency where hyperglycemia -> glucosuria causes increased absorbable solute
diabetes mellitus
compounds that stimulate thirst by direct action on neurons in the thirst center
dipsinogenic
increased plama renin causes what
direct affect on thirst center
what is the diagnostic plan
document P&P exists data base find specific gravity perform urine concentration tests perform special diagnostic tests
what is pollakiuria
frequent urination
when do you give dextrose
get animal peeing when in renal failure
what is glucosuria
glucose in urine
increased production of glucocorticoids where ADH is inhibited at the collecting ducts
hyperadrenocorticism
cushing's disease is otherwise known as and causes what
hyperadrenocorticism; bilateral, patterned alopecia, pendulum belly, forlorn look, polyuric, Pd, Pp
cancer where ADH is inhibited - mineralization of the kidney -> chronic renal failure
hypercalcemia
the thirst center is located where
hypothalamus
alcohol causes inhibition of ADH release; acts as a diuretic effect
iatrogenic
induced by humans; usually drug-induced
iatrogenic
steroids increase/decrease appetite so cause polyphagia
increase
primary thirst causes what
intracellular dehydration and left atrial volume and pressure receptors decrease in blood volume induces thirst
glomerular filtrate with a specific gravity equal to plama which is 1.008 to 1.012
isosthenuric
furosemide is otherwise known as and can't do what
lasix; macromolecule so can't cross blood brain barrier
what are some examples of diuretics which cause diuresis
mannitol, dextrose, furosemide
disease where loss of countercurrent multiplier system
medullary washout
diabetes insipidus can be caused by what two things bc ADH
neurogenic; nephrogenic
what are some causes of pathologic thirst
neuronal irritation; compulsive water drinking; increased plasma renin; hypercalcemia; thoracic caval constriction
what do you do when you are giving the ADH response test
obtain urine SG, withhold food/water, give SQ vasopressin tannate, take urine SG at 30 min
excessive thirst persisting for long periods of time; constant drinking
polydipsia
passage of a large volume of urine in a given time; urine has decreases specific gravity
polyuria
Pd rests from a _____
primary Pu
pathologic thirst causes what
primary polydipsia
generate secondary polydipsia, stress induced so it causes them to drink a lot
pseudopsychogenic polydipsia
tubule is unresponsive to ADH
pyometra
what does vasopressin tannate do
reabsorb fluid and concentrate urine
water is reabsorbed along concentration gradients established in ______ which decreases _______
renal medulla; osmolality
what are two examples of dipsinogenic
renin and angiotensin
what is the more common cause of Pd
secondary thirst
mannitol is what and allows for what
small and allows to cross blood brain barrier
what are pituicytes and what is their function
specialized nerves found in hypothalamus and produce ADH
a desire for water
thirst
what can be used to rule out primary polydipsia
water deprivation test
what are two urine concentration tests
water deprivation tests ADH response test
Pd and Pu appear in polysystemic disorders where they manifest in a disorder in what
water homeostasis
what is important in taking a PE
weight and hydration status!!! also PCV, urine specific gravity
when should you terminate the water deprivation test
when concentrated urine is produced, weight loss of 5-7% occurs, there is an increase in plasma protein or osmalality
osmotic diuresis is what
will drink more
what is normal specific gravity
1.015
animals with urine specific gravity > ? are not Pu
1.035
what are the two principles of the Bar-Scene syndrom
1st - water in...water out 2nd overhydration vs. dehydration (intracellular)
a 25 pound dog should give out _____L of fluid filtered by glomeruli each day but less than _____mL is excreted as urine
68; 500
what is produced by pituitocytes that increases extracellular fluid osmolality --> increased ADH release --> increased collecting tubule permeability --> water to be reabsorbed
ADH
what are two Renal Concentrating Mechanism
ADH - Osmoreceptor Control System Countercurrent System
what lies adjacent to the thirst center and controls extracellular fluid osmolality
ADH Control center
the Countercurrent System is
Loops of Henle
secondary thirst causes what
anticipates water needs prior to actual deficiencies
