Polyuria/Polydipsia

With lots of _____ and high concentrations of _____ and _____, lots of water will move out of the renal tubules and a large volume of concentrated urine will be made

aquapoins; Na; BUN

ADH in the renal medulla causes _____ to be inserted into the distal tubule and collecting ducts

aquaporins

_____ are pores through which water moves, movement of water through these pores is a passive process

aquaporins

MWDT absolute endpoints: 1. _____ (ABSOLUTE contraindication) 2. plasma osmolality >_____ mOsm/kg - ADH secretion should be maximal when this is reached 3. USG >_____ in dogs and >_____ in cats 4. loss of >_____% body weight

azotemia; 320; 1.030; 1.035; 5

With Lepto you expect them to become _____ or have elevated _____ enzymes

azotemic; liver

If they are eating a lot of _____ food then there can be a lot of water intake through what they are eating

canned

Primary polydipsia is NOT very _____

common

As urine goes down the descending LOH it is highly _____

concentrated

If there are maximal ADH concentrations present, urine will be excreted as very _____

concentrated

The more _____ the renal medulla, the more water will be pulled out of the renal tubules and the more _____ the urine will be

concentrated; concentrated

Causes of ADH deficiency (central DI): 1. _____ 2. _____

congenital; acquired

At the beginning and every 2 hours of the MWDT you should: 1. measure _____ - if this is high you CANNOT do the test, you ONLY do this in the BEGINNING 2. check _____ - if creatinine is normal 3. serum _____ 4. check _____ - if they become dehydrated you are done 5. _____ bladder 6. _____

creatinine; USG; osmolality; hydration; empty; weigh

ALWAYS measure _____ the morning of the MWDT, if they are _____ do NOT do the test!!!

creatinine; azotemic

Causes of osmotic diuresis: 1. _____ - see glucose in the distal tubules 2. primary renal _____ - kidney problem where the renal tubules cannot reabsorb the glucose 3. _____ renal failure 4. _____ diuresis - relieved urethral obstruction

diabetes mellitus; glycosuria; chronic; post-obstructive

As urine comes back up the ascending LOH it is very _____

dilute

If there is no ADH present then urine is not concentrated as it moves through the distal tubule and collecting duct and the urine that is excreted at the end will be very _____ and will have a USG of _____

dilute; 1.000

NDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: _____ respond (USG <_____) 3. post-ADH: _____ respond (USG <_____)

dilute; 1.006; can't; 1.006; can't; 1.006

Complete CDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: no _____ (USG <_____) 3. post-ADH: _____ (USG >_____)

dilute; 1.006; response; 1.006; respond; 1.018

Partial CDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: some _____ (USG _____-_____) 3. post-ADH: more _____ (_____-_____% increase in USG)

dilute; 1.006; response; 1.008-1.020; response; 10-50

If there is _____ urine the urine sediment exams are NOT reliable for dx of UTI, therefore a urine _____ needs to be done

dilute; culture

Types of primary polyuria: 1. osmotic _____ 2. _____ deficiency (central DI) 3. lack of _____ response

diuresis; ADH; ADH

If they are eating dry food, most of their water intake will be through _____

drinking

The basic problem with primary polyuria is that they are _____ too much

drinking

Get a good hx: 1. _____ - include topical glucocorticoids 2. _____ change 3. other problems 4. _____uria vs _____uria vs _____

drugs; diet poly; dys; incontinence

_____ is another factor of normal water metabolism

eating

Dx PU/PD: 1. establish that PU/PD _____ 2. get a good _____ 3. thorough _____ 4. minimum _____ 5. test for specific _____

exists; hx; PE; data base; diseases

DDAVP response test = _____ ADH

exogenous

_____ fluid osmolality is the main thing that controls ADH, this is a very sensitive system

extracellular

Other factors of water output: 1. _____ 2. _____ tract - esp. in hot weather due to panting

feces; respiratory

Drugs that cause PU/PD: 1. _____ - PU/PD is the #1 side effect of these drugs 2. _____ 3. _____ - increase H2O output for a living, so the dog is going to drink more

glucocorticoids; phenobarbital; diuretics

Things that interfere with secondary messengers thus causing secondary NDI: 1. _____Ca 2. _____K 3. _____- due to toxin that E. coli releases 4. _____ - interferes with the function of tubules and can cause PU/PD 5. _____ - can cause PU/PD in the absence of any other clinical signs

hyper; hypo; pyometra; pyelomephritis; Lepto

Conditions that cause low Na/BUN and thus secondary NDI: 1. _____ - classic example of low Na 2. _____ protein diet - leads to low BUN and thus increased water consumption 3. _____ failure - leads to low BUN 4. renal medullary _____

hypoadrenocorticism; low; hepatic; washout

Ways to est. that PU/PD exists: 1. measure water _____ - have to be strict about the water sources 2. _____ (collect at home) - this should be a first morning urine sample

intake; USG

Normal water metabolism is an _____ system

integrated

When urine is first made it enters the proximal tubule and is _____ (same concentration as _____, USG of _____)

isosthenuric; serum; 1.010

Thirst kicks in _____ than ADH secretion, but is controlled similarly

later

Medullary washout occurs due to _____ Na/BUN

low

_____ protein diets can decrease BUN and thus increase drinking behavior

low

Secondary nephrogenic DI = ADH receptor _____

malfunction

Lack of ADH response =

nephrogenic DI

In the distal tubules and collecting ducts water is pulled out of the tubules by an osmotic force

osmotic diuresis

*See Annabelle's other results. What is your interpretation of the MWDT?*

partial central DI

When you have a more dilute _____ there is not much secretion of ADH

plasma

Stimulation of ADH secretion: 1. _____ osmolality #1 2. _____% decrease in blood volume

plasma; 10

Unknown mechanisms that cause secondary NDI: 1. _____ 2. _____ 3. _____

polycythemia; hyperadrenocorticism; hyperthyroidism

ADH comes from the _____

posterior pituitary

The problem is that the patient cannot concentrate their urine, so they are urinating a lot and are drinking to prevent dehydration

primary polyuria

DDAVP response test is only used when 3 differentials remain: 1. _____ 2. _____ 3. _____

psychogenic polydipsia; CDI; primary NDI

Types of primary polydipsia: 1. _____ - behavioral issue, anxiety issue 2. _____ failure - as a manifestation of hepatic encephalopathy

psychogenic polydipsia; hepatic

ADH will make a dog with _____ concentrate its urine, so it can be difficult to differentiate between _____ and _____

psychogenic polydipsia; partial CDI; psychogenic polydipsia

Modified water deprivation tests are ONLY designed to differentiate between: 1. _____ polydipsia 2. _____ DI 3. _____ DI

psychogenic; central; primary nephrogenic

Primary nephrogenic DI = lack of ADH _____

receptors

With NDI they do NOT have ADH _____, so urine will remain very _____

receptors; dilute

Most common causes of primary polydipsia in cats: 1. _____ failure 2. _____ 3. _____

renal; diabetes mellitus; hyperthyroidism

Most common causes of primary polydipsia in dogs: 1. _____ failure 2. _____ 3. _____

renal; hyperadrenocorticism; diabetes mellitus

Something is going on in the body that is preventing the kidneys from responding to ADH

secondary nephrogenic DI

_____ NDI should NOT even be a consideration b/c you have to rule out _____ first before you do a MWDT!

secondary; secondary

Normal water metabolism is a precise regulation of: 1. water intake, mainly by _____ 2. water output, mainly by _____

thirst; vasopressin

No _____ limit exists for the MWDT, so an emergency or 24 hr clinical may be utilized

time

_____ tract infections can cause PU/PD

urinary

*What test do you want to do next if CBC/proflie are unremarkable and you have done a UA?* See "Annabelle" Buff case!!!

urine culture

You would put Addison's disease higher if the dog is _____

vomiting

Causes of secondary nephrogenic DI: 1. medullary _____ 2. interference with ADH _____ messenger system 3. _____

washout; secondary; unknown

PU/PD can be defined clinically by measuring how much _____ there is

water intake

What is the main function of anti-diuretic hormone (ADH) aka vasopressin?

water retention

ADH (vasopressin) increases _____ as well

BP

Minimum data base for a PU/PD patient: 1. _____ 2. profile with _____ - a measure of kidney function 3. _____ 4. urine _____

CBC; SDMA; UA; culture

Interpretation of DDAVP response test: 1. dramatic (>50%) decreased water intake and/or increased urine concentration: strong evidence of _____ 2. moderate response: _____ 3. _____ - will respond

CDI; partial CDI; psychogenic polydipsia

Primary polydipsia interpreation: 1. initial: USG _____-_____ 2. endpoint: _____ (USG >_____) 3. post-ADH: N/A

1.002-1.020; concentrated; 1.030

Increased thirst: 1. dogs: >_____ ml/kg/day 2. cats: > _____ ml/kg/day

100; 45

*If it is a dog and the culture is negative, what is your top differential?* 1. DM 2. hyperadrenocorticism 3. Addison's disease 4. hyperthyroidism

2 - want to do an ACTH stim test

Protocol for DDAVP response test: 1. measure water intake for _____-_____ days 2. tx with DDAVP for _____-_____ days 3. monitor water intake and urine output on days _____-_____ to see if they are responding to exogenous ADH hormone

2-3; 5-7; 5-7

Steps of the modified water deprivation test: 1. restrict water slowly over _____-_____ days to get them down to _____ ml/kg/day 2. at start take _____ water away 3. make sure an _____ endpoint is reached 4. if not concentrated at endpoint, give _____ and see what happens

2-4; 100; all; absolute; ADH

If you have to send them home while doing a MWDT at the end of the day you should: 1. _____ ml/kg/water/hr unobserved 2. next morning - _____, take away _____, _____ test

2.75; weigh; water; continue

Patients become PU/PD when they lose _____ of their nephrons

2/3

Factors of plasma osmolality that stimulate ADH secretion: 1. _____% increase in ECF osmolality 2. max: _____ mOsm/kg

2; 320

Patients become azotemic when they lose _____ of their nephrons

3/4

Once you hit a plasma osmolality of _____ you have maximal ADH secretion

320

Things you have to have to respond to ADH: 1. >_____% nephrons 2. _____ renal medulla 3. ADH _____ on the tubules to be able to respond

33; hypertonic; receptors

*Which of the following is NOT needed to concentrate urine?* 1. adequate ADH 2. adequate ADH response 3. adequate Na 4. adequate BUN 5. adequate Ca

5

Tests for specific diseases: 1. _____ (dogs) - Cushing's can cause only PU/PD and nothing else 2. _____ (cats) - ALWAYS

ACTH stim; T4

With complete CDI at the endpoint there will be no response b/c they have no _____ so they cannot concentrate their urine

ADH

With primary nephrogenic DI they have lack of ADH receptors, therefore they cannot respond to _____

ADH

*What is the main hormone that helps concentrate urine?*

ADH (vasopressin)

Things needed to concentrate urine: 1. enough _____ 2. response to _____

ADH; ADH

Any time you have a huge abscess filled with _____ you can have PU/PD

E. coli

A modified water deprivation test should be done _____!!

LAST

DDAVP response test is an option to _____

MWDT

*See Annabelle's MWDT results. Has an endpoint been reached?*

NO - she has not concentrated her urine, plasma osmolality is still less than 320, and she has not lose 5% of her body weight

*A 30 kg dog eats a mix of dry and canned food. he drinks 2400 ml water/day. Is this PU/PD?*

NOT sure b/c they are eating a mix of dry and canned food and you cannot tell how much water they are getting from their diet

If you do not have adequate concentrations of _____ and _____ you can see medullary washout

Na; BUN

_____ and _____ are the main things that must be present in the medulla

Na; BUN

_____ and _____ in the renal medulla are important in concentrating ability

Na; BUN

Diabetes insipidus is a _____ disease

RARE

_____ will increase BEFORE creatinine

SDMA