L39: urinalysis

what urinalysis component corresponds to concentrating ability?

USG measurement

what urinalysis component corresponds to proximal tubule reabsorption?

dipstick analysis

what urinalysis component corresponds to tubular damage?

detection of casts

what urinalysis component corresponds to urinary tract inflammation?

presence of pyuria

what urinalysis component corresponds to glomerular (barrier) dysfunction?

significant protienuria (albuminuria)

why do we want fresh urine for a urinalysis?

cells deteroriate and start to form crystals wehn sample left for too long

what are the core components for a urinalysis?

1. visual

2. USG

3. dipstick

4. sediment

what are the collection methods for a urinalysis?

1. free catch

2. cystocentesis

3. catherization

which collection method would you expect to see bacteria in urine sample analysis?

free catch; expect to see bacteria

which collection method is most sterile for urinalysis; what does presence of bacteria mean?

• cystocentesis

• if have bacteria indicative of infection

while catherization is a sterile method of urine collection, from what part of the urinary tract will the bacteria be from if in a sample?

bacteria from bladder and upper urinary tract

what does it mean if urine color is colorless?

dilute urine

what does it mean if urine color is light yellow?

normal

what does it mean if urine color is dark yellow?

normal, concentrated; would want USG

what does it mean if urine color is red and clear?

1. hemoglobinuria

2. myoglobinuria

what does it mean if urine is red and cloudy?

hematuria

what does it mean if urine is orange to brown?

bilirubin

what does it mean if urine is coffee brown?

myoglobinuria

how else can urine appear if myoglobinuria is present?

red clear urine

what does it mean if urine clarity is clear?

expected, solutes dissolved

what does it mean if urine clarity is hazy to cloudy?

suspended particles present (cells, crystals)

USG by refractometry measures…

solute concentration proportional to the light refraction of dissolved solutes or solids

what 4 reagent strips are not accurate for urine chemical assays by dipstick?

1. leukocytes

2. nitrites

3. ubobilinogen

4. specific gravity

why are leukocytes not accurate in urinary dipstick tests?

often yields false positives

what type of urine do carnivores typically have?

acidic

what type of urine do herbivores typically have?

alkaline (UNLESS MILK DIET)

what values are a red flag in dilute urine?

+1/+2 protein and +1 bacteria

what USG is telling you it is dilute urine?

1.005-1.015

what change in pH can occur in a delayed analysis?

alkalinuria as bacteria through urea metabolism increase pH longer they are present in sample

what are the categories in which proteinuria can occur?

1. pre-renal

2. glomerular

3. tubular

4. post-renal

in dogs what is protein level is normal?

some can have trace to 1+

what proteins are detected best by urinaysis?

• albumin = best

• globulins will also be detected

what issue can result with proteinuria testing with alkaline urine?

false positives in alkaline urine

what does a positive for proteinuria in a urinalysis test indicate about the kidneys?

glomerular, tubular, or mucosal damage due to inflammation

pre-renal cause of proteinuria

small proteins (hemoglobin and myoglobin dimers) pass through glomerulus

*NOTHING WRONG WITH KIDNEYS

what is the only proteinuria that causes hypoalbuminemia?

glomerular

glomerular proteinuria

glomerulus is not working and allowing large proteins such as albumin and globulins to pass through

glomerular proteinuria can be quantified by…

• UPC test to determine issue of kidney area

• will also be seen on bloodwork

tubular proteinuria

small globulins not reabsorbed by proximal tubules

what is tubular proteinuria often associated with?

acute renal diseases (toxins and hypoxia)

what is important to note about tubular proteinuria?

DOES NOT PRODUCE HYPOALBUMINEMIA

what toxin is often associated with tubular proteinuria?

ethylene glycol

where is hemorrhagic or inflammatory proteinuria taking place in the body?

bladder only

hemorrhagic or inflammatory proteinuria

albumin and globulins are present in the urine due to damage or inflammation in the urinary trac

what conditions cause pre-renal proteinuria?

1. hemoglobinuria with IMHA

2. myoglobinuria

3. Bence Jones (lymphoid neoplasms)

what conditions cause glomerular proteinuria?

*TYPICALLY CHRONIC

1. glomerulonephritis

2. glomerular amyloidosis

what conditions cause tubular proteinuria?

acute tubular toxicity

what conditions cause hemorrhagic or inflammatory proteinuria?

1. hematuria

2. pyuria

A dog presented for not eating or

drinking; it was dehydrated.

Evaluate serum and USG first.

This dog’s proteinuria is most likely…

glomerular proteinuria

what does UPC need to be?

urine sediment needs to be inactive ( no RBC, bacteria, or WBC present)

what causes need to excluded of proteinuria to trust UPC and what does it tell you?

• excluded: pre-renal, tubular, hemorrhagic

• tells you: severity of glomerular proteinuria

what physiological process are we expecting when examining urine for glucose?

expect negative reaction as filtered glucose should be reabsorbed by proximal tubule

what plasma glucose level is expected in renal glucosuria?

plasma glucose is WRI

what is the mechanism for renal glucosuria?

1. glucose enters ultrafiltrate

2. tubular disease or defect

3. defective glucose reabsorption

osmotic diuresis

glucose in tubular fluid reduces H20 resorption by tubules leading to polyuria

what ketone in urine does chemical assay detect?

acetoacetate

what ketone does urinalysis not detect and why is that an issue?

beta-hydroxybutyrate; issue because this is elevated in DKA

why are hepatocytes formed in urine?

ketone bodies from fatty acid metabolism

what ketone bodies are formed in urine?

1. acetoacetate

2. beta-hydroxybutyrate

3. acetone

ketonuria

excess catabolism of fatty acids by hepatocytes leads to formation of ketones

what promotes ketonuria?

decreased insulin activity and increased glucagon activity

when is it common to see ketonuria?

1. diabetes mellitys

2. bovine ketosis

what electrolyte changes happen with ketonuria?

1. hyponatremia

2. hypokalema

hemeturia

1. RBC in urine sediment

2. alkaline

3. USG less than 1.015 (very dilute)

what is the appearance of hemeturia?

• plasma= clear

• intact RBC

hemoglobinuria

free hemoglobin in sediment; expect patient to have anemia

hemoglobinuria appearance

• lysed RBC

• plasma = red

myoglobinuria

free myoglobin in sediment; expect evidence of muscle damage in history

what do we expect to be elevated in myoglobinuria?

muscle enzymes (CK)

appearance of myoglobinuria

• plasma = clear (no hemolysis)

• nothing to do with RBC!

what are the causes of bilirubiuria?

1. hemolytic icterus

2. hepatoobiliary disease

hemolytic icterus

bilirubin formation occurring faster and greater rate than bilirubin excretion into bile

hepatobiliary disease

issue with gallbladder leads to impaired bilirubin excretion where bilirubin is regurgitated into plasma

A 6-yr-old horse presented because it

passed red urine. Initial CBC results

revealed anemia (Hct 10 %) and

leukocytosis. The data indicate the

horse has

prerenal proteinuria and intravascular hemolytic disease

A 6-yr-old cat presented

with pale mucous

membranes, and

mmmm regenerative anemia. Based

on all information, what is

the most likely cause

extravascular hemolytic disorder

pyuria

leukocytes in urine

hematuria

erythrocytes in urine

bacteriuria

bacteria in urine

cylinduria

casts in urine

why might epithelial cells be present in urine?

can be normal, inflammatory, or neoplasia

crystalluria

crystals in urine

pyuria is often concurrent with…

hematuria

what area of the urinary tract are you suscpious of if you see leukocytes or erythrocytes from a voided collection?

genito-urinary tissues

what structures of the urinary tract are you suspicious of being the problem if you see leukocytes or erythrocytes in a sample from catheter?

1. urethra

2. bladder

3. kidneys

4. male (prostate)

what structures of the urinary tract are you suspicious of as the problem if you see leukocytes or erythrocytes in a sample from cytocentesis?

1. bladder

2. kidneys

3. male (prostate)

what happen to RBC in dilute (<1.015)  or alkaline urine?

RBC lyse 

what type of change is crenation?

in vitro

A 3-yr-old cat presented with

anorexia and polyuria. Initial CBC

detected a mild erythrocytosis. The

provided data indicate there is a

hemorrhage in urinary tract

what do you need to do if you have bacteria and no WBC?

culture

when in a cysto sample are we thinking red flag?

if +1 bacteria with no WBC tells you most likely contamination of the sample

casts

 Cylindrical molds of renal tubules, made of mucoprotein ± cells

A male dog was presented

because it occasionally

passed red urine. The UA

data indicate there is

inflammation in the genital or urinary tissue

hyaline cast

 pure Tamm–Horsfall protein, not

pathologic

casts are a clue for…

tubular injury or degeneratin

granular casts

fine or coarse; active tubular damage or epithelial degeneration

cellular casts

epithelial, leukocyte, erythrocyte

(cells trapped in protein; rare but significant)

waxy casts

 advanced, chronic tubular degeneration

what type of epithelial cell in urine would you expect from distal urethra or genital tissues?

squamous

what type of epithelial cells would you expect in a urine sample from renal pelvis to urethra or genito-urinary tissues?

transitional