Urinary Flashcards
clinical presentations of UT disease
stranguria - straining to urinate
hematuria - blood in urine
dysuria - discomfort/diffulcty when urinating
pollakuria - frequent abnormal urination
periuria - urination at inappropriate sites
anuria - failure of urine production by kidneys
oliguria - reduction in urine production
polyuria - increased urine production
stranguria
dogs - bacterial cystitis/urethritis, urinary calculi
cats - idiotpathic cystitis (stress) urolithiasis
if bladder large then bad
bladder inflammation - small bladder, thick wall, small squeeze elicits urination
bladder atony/lower motor neuron disease - large flaccid bladder, gentle squeeze elicits urination
obstruction - large tense bladder, urine not easily expressed
calcuil or mass - irregular hard masses felt, may have grating feeling
hematuria
trauma
rodenticides
genital sources
coagulopathies - bleeding from other sites
initial hematuria - lower UT
terminal hematuria - upper UT
total hematuria - upper UT, diffuse bladder disease, prostate or proximal urethra, coagulopathies
differentiate from hemoglobinuria and myoglobinuria
methods of urine collection
free catch - easy, owner can do, non traumatic or invasive, but risk of non-complicance, contamination, variable volume, risk of damage if manual expression
cystocentesis - quick, easy in cats, aseptic (culture), lower risk of infection than catheter, but a bit harder, may cause haemorrhage - contraindicated in severe bladder disease or coagulopathy
catheter - low bacterial contamination, big sample, but harder to do, risk of infection, not for culture because lower UT contamination. difficult in female cat - blind insertion
urinalysis artefacts
crystals - calcium oxalate, struvite
refrigeration artefacts - in vitro crystal formation, inhibition of enzyme reactions, falsely increased USG
room temperature artfacts - bacteria - overgrowth, metabolised chemicals, altered culture results
urine collection timing
early morning most concentrated (expect higher USG)
highest yield of cells
cells may be altered because of prolonged exposure to pH and osmolarity of urine (sitting in bladder longer)
glucouria may be more prominant post prandial
urinalysis - areas assessed
USG - loop of henle and distal tubule
dipstick - proximal tubules and grlomerular function
biochem - glomerular function
normal USG
dog - 1.015 - 1.045
cat - 1.045 - 1.060
in light of hydration -
isothenuria - 1.008 - 1.012
hyposthenuria - <1.008
well concentrated - >1.030
normal pH
high - >7.5 - UTI with urease producing bacteria –> metabolic alkalosis (but normal in herbivores)
low - <7 - UTI with acid producing bacteria –> metabolic acidosis (normal in carnivores)
crystalluria
precipitate when urine saturated with dissolved minerals
may get without disease
prolonged storage or cold artefact
magnesium ammonium phosphate - struvite - UTI or diet
cystine - hexagonal - abnormal, proximal tubular defect in amino acid transport
calcium oxalate dihydrate - envelope shape - acidic urine, urolithiasis, hypercalcuria, hyperoxaluria
calcium oxalate monohydrate - picket fence - ethylene glycol ingestion (may be normal in horses)
calcium carbonate - yellow brown crystals, alkaline urine - common in horses
bilirubin - orange-reddish brown - routinely seen in low numbers in dogs, abnormal in cats
ammonium biurate crystals - routine in dalmatians
renal tubular casts
proteinaceous plugs of dense mesh like mucoprotein
accumulate in distal nephron
normal in low numbers
increased - tubular disease
epithelial cells of UT
Transitional - renal pelvis, bladder, ureter, proximal 2/3 urethra
squamous - distal 1/3 urethra
pyuria
high leukocyte count
uroliths
calculus in urinary tract
usually calcium carbonate in horses and rabbits
ammonium sulphate or calcium oxalate in dogs and cats
bladder - cystolith
lower UT signs - dysuria, pollakuria, hematuria
may be palpable
ureters - uretoerolith
renomegaly and failure if bilateral
kidney - nephrolith
incidental usually
may have pyleophritis, pain, pyuria, pyrexia
urethra - urethrolith
lower UT signs
abdominal discomfort
licking
most severe - obstruction –> post renal azotemia –> acute kidney injury –> uremia
urethra palpable per rectum
urolith diagnosis
palpation
radiograph -
radiopaque - struvite, calcium oxalate, calcium phsphate
radiolucent - ammonium urate, cystine
ultrasound - easy to miss them
emergency treatment - urinary obstruction
emergency unless only partial
stabilise - manage hyperkalemia, fluid therapy
retrograde hydorpropuslsion - push stones backwards with catheter
urethrostomy - for recurrent problems
blood volumes
dog - 88ml/kg
cat - 66ml/kg
aims of fluid therapy
maintenance of normal physiology
improvement of organ function
correction of electrolyte disturbances
corretion of hypovolemia
correction of acid base disturbances
maintenance fluid rate
2.5ml/kg/hour = 60ml/kg/day
estimating fluid losses
no signs - <5% deficit
tacky mm - 5-6%
skin tent, sunken eyes - 6-8%
increased pulse, cold peripheries - 8-10%
weak pulses - 10-12%
collapse - 12-15%
types of fluid
CRYSTALLOIDS
isotonic - lactated ringers
shock, diruesis, anaesthesia, maintenance
hypotonic - sodium chloride
not used often
hypertonic - saline
drains water from interstitial space
restoration of BP, increased myocardial contractility, CO and oxygen delivery
large animals mostly
COLLOIDS
hetastarch
supports circulating blood volume
severe hypovolemia
more rapid initial re-expansion of volume and supports circulation longer than colloids, but no evidence actually better
BLOOD PRODUCTS
whole blood, packed RBCs, fresh frozen plasma, cryoprecipitate
speed of fluid admin
shock - 60-90ml/kg/hour or 1/2 deficit in first 1-2 hours and rest over 24-48 hours
chronic losses - replace over 3-4 days
anaesthetic maintenance -
dogs - 5-20ml/kg/hour
cats - 3-9ml/kg/hour
IV complications
extravasation
thrombosis
thrombophlebitis
infection
emboli
exsanguination
contraindications - fluid therapy in anaethestetic
cardiac patients - risk of volume overload
risk of anaphylactic repsonse
risk of interference with clotting tests (colloids)
may cause fluid overload in cats
cost
PUPD - primary polyuria
most common
lack of ADH production by hypothalamus –> can’t concentrate urine - primary central diabetes insipidus
inability of renal cells to respond to ADH - nephrogenic diabetes insipidus
inability of renal cells to repsond to ADH secdonary to another process -
reduced sensitivity - e coli toxins, cushings
interference with ADH action - hypercalcemia, hypokalemia
ADH receptor downregulation - obstruction at ureter or bladder, hypokalemia
osmotic diuresis - increased concentration of solutes in glomerular filtrate to more water excreted -
medications - mannitol
diabetes mellitus
CKD
post obstructive diruesis (measure BUN)
liver failure
reduced medullary concentration gradient -controlled by Na+ and urea in medulla
IVFT
Steroids
liver failure
Addisons
PUPD - primary polydipsia
uncommon in small animals - more horses
cerebrocotrical dysfunction - central lesion in hypothalamus (thirst centre)
also endocrine disorders
PUPD ddx
diabetes mellitus
CKD
liver failure
central diabetes insipidus
nephrogenic diabetes insipidus
hypercalcemia
hypokalemia
iatrogenic
Addisons
Cushings
e coli toxicity
PUPD pathophysiology
plasma osmolality - determines blood pressure
osmolality integrated into thirst centre of brain
hypothalamus –> produces ADH –> kidneys –> regulates reuptake of water
so need functioning hypothalamus and kidneys
CKD
older animals
signs -
weight loss
inappetance
PUPD
oral ulcers - poor prognosis
diagnosis -
biochem, hematology - renal azotemia, non-regenerative anemia, hypokalaemia, hyperphospahtemia
USG - low
proteinuria
BUN and serum creatinine
stage 1 - no clinical signs
2-4 - easier to pick up on exam
pyelonephritis
inflammation of renal pelvis with or without bacterial infection
signs -
PUPD - bacterial endotoxins interfere with ADH and inflammation interferes with medullary osmotic gradient
lower UT signs - hematuria, pollakuria, dysuria, stranguria
renal, lumbar, spine pain
renomegaly
lethargy
diagnosis - ultrasound
hematology - left shift inflammatory leukogram
urine culture and sensitivity
pyometra
usually e coli infection
older entire bitches
signs -
open - mucoid to purulent discharge at vulva
closed - lethargy, pyrexia, inappetence, vomiting and diarrhoea, PUPD
diagnosis -
left shift leukogram - presence of immature neutrophils in blood - increased demand
azotemia
imaging
hyperthyroidism
cats over 7yo
signs -
PUPD
polyphagia with weight loss
behavioral chanegs
intermittent vomiting and diarrhoea
diagnosis -
decreased BCS
tachycardia, murmur, gallop rhythm
goitre
increased ALT and T4
Cushings
middle aged older dog
signs -
PUPD
Polyphagia
pot belly
skin thinning
hair coat changes
diagnosis -
increased ALP
USG <0.020
acth STIM
loe dose dexamethasone suppression test
urine cortisol:creatinine
Addisons
younger dogs
signs -
vague
waxing and waning GI signs
collapse
shock
diagnosis -
Na:K ratio <23
ACTH stim
diabetes mellitus
signs -
weight loss
polyphagia
lethargy
PUPD
Diagnosis -
hyperglycemia
urine - glucose, ketones
fructosamine in blood - expensive
hypercalcemia
signs -
PUPD
variable depending on cause
Causes (HOGSINYARD) -
Hyperparathyroidism
osteolysis
granulomatous disease
spurious sample
idiotpathic - cats
neoplasia
young animals - growth
addisons
renal disease
hypervitaminosis D
diagnosis - increased total calcium
liver disease
signs -
PUPD
non specific depending on cause
diagnosis -
increased liver enzymes
decreased urea, cholesterol, albumin and glucose
bile acid stim
imaging
normal drinking
40-60ml/kg per day
(abnormal = 2x maintenance - 100ml/kg/day)
biochem
urea/creatinine - renal failure
hyperglycemia - diabetes mellitus
T4 - hyperthryoidism
hypercalcemia - neoplasia and others
high ALP/cholesterol - cushings
azotemia
increased nitrogenous compounds in blood - urea and creatinine
pre-renal - dehydration/hypovolemia, shock - blood indicators of dehydration (PCV, total protein, lactate)
renal - glomerular disease, tubular disease, interstitial disease - blood indicators of dehydration
post renal - obstruction, rupture of UT - dysuria, usually reversible
renal failure - pathophysiology
excretory failure - due to diminished GFR - increased BUN and creatinine (azotemia)
metabolism failure - failure to catabolise polypeptide hormones insulin, glucagon, GH
failure to synthesis -
failure to make calcitrol –> secondary hyperparathyroidism
failure to make erythropoietin –> anemia
accumulation of uremic toxins -
urea - weakness, anoerxia, vomiting, glucose intolerence
creatinine - weight loss, platelet dysfunction
PST, insulin, GH - osteodystophy, hyperinsulinemia, insulin resistance
others –> anorexia, uremic breath, encephalopathy, impaired, erythropoiesis, abnormal platelet function
acid:base homeostasis -
inability to reabsorb bicarb –> metabolic acidosis
systemic hypertension -
RAAS dysfunction - effect on systemic blood pressure
approach to renal failure - exam and testing
clinical exam -
dehydration - tacky mm, CRT
CV status
signs of bleeding disorders
assess lower UT
fundus - signs of hypertension
abdominal palpation
transrectal to assess left kidney (horses and cattle)
biochem and hematology -
azotemia - BUN and creatinine
electrolyte abnormalities
anemia
acid-base imbalance
platelet disorders
USG - low
response to fluid therapy - pre-renal should resolve
proteinuria and protein:creatinine ratio
chronic vs acute kidney failure
acute -
sudden onset
polyuria –> oliguria/anuria
may not have time to get to advanced uremia signs
may have signs of urinary or abdominal trauma
may have history of ingestion of a known toxin
chronic -
long term weight loss
PUPD
uremia
history of vomiting
progressive weakness and pale mm
uremia signs
PUPD
dehydration
anorexia
weight loss
vomiting
halitosis
oral ulceration
GI bleeding
weakness/lethargy
pale mm
neurological signs
bird - dropping colours
white urates - normal
green - biliverdinuria - severe hepatic disease
golden/brownish-yellow - hepatic disease or vitamin administration
red/brown - lead toxicity, nephritis, polyomavirus, warfarin type poisons
Feline Urinary Tract Disease (FLUTD)
collection of conditions affecting bladder or urethra in cats -
urolithiasis
bacterial infection
urethral plugs
anatomical defects
neoplasia
feline idiopathic cystitis
FLUTD - signallment
usually <10yo
neutered
overwight
inactive
mainly indoor
dry diet
multi cat house
stress
FLUTD - pathogenesis
unknown, suggested -
neurogenic inflammation
mucosal defects - increased bladder wall permeability
neuroendocrine imbalance
crystalluria
struvite present in over half of cases but also in lots of healthy cats
FLUTD - role of stress
neuroendocrine trigger
environmental change –> stress –> change in bladder lining –> pain, swelling, vascular leakage, irritation –> more stress –> repeat
substances in urine exacerbate inflammation
inadequate response of nervous system to cortisol feedback
FLUTD - signs
lower UT -
dysuria
pollakuria
hematuria
stranguria
periurea
behavioural -
loss of litter training
aggression
excessive grooming
appearance of constipation
stilted gait - discomfort
abdominal pain
FLUTD - diagnosis
history and signalment important
physical exam -
non-obstructed - small bladder, no systemic signs unless concurrent disease
obstructed - distended firm bladder, dicoloured and swollen penis, dehydration, systemic illness, bradycardia
rule out uroliths, neoplasia and infection
urinalysis
hematology and biochem - unremarkable
radiography
ultrasound - bladder
cytoscopy
Diagnosis of exclusion
FLUTD - Urethral Obstruction
uroliths - struvite or calcium oxalate
urethral plugs - protein colloid mucoids (RBCs, WBCs and crystal material on cytology)
idiopathic - functional or non-physical obstruction - spasm, mucosal oedema
FLUTD - management
pain relief - 5-7 days
flush bladder - saline or lidocaine
increase water intake long term
decrease stress
environmental enrichment
cystease - may protect bladder lining
