Urinalysis Clin path2

Physical urinalysis

gross evaluation, USG determination

Chemical urinalysis

dipstick reagent pad analysis, ictotest, UP:UC

Microscopic urinalysis

evaluation of sediment

For best results of urinalysis?

analyze within 30 minutes

Urine is expected to be clear in all healthy animals except what species?

horses

True or false: You can use the dipstick to determine specific gravity

false

What is reliable on the urine dipstick?

protein, glucose, ketones, pH, bilirubin, hemoprotein

Carnivores have increased protein catabolism which makes their urine pH more?

acidic (6-7.5)

Ruminants have decreased protein catabolism which makes their urine pH more?

alkaline (7.5-8.5)

Infection with urease-producing bacteria results in _ of the urine?

alkalinization

What can cause a false positive for urine protein?

very alkaline urine or some cleaning agents

Always interpret proteinuria in the context of?

USG

True or false: some glucose can be in the urine

False

Glucose is efficiently reabsorbed in the?

proximal tubule

Glucosuria is present if?

renal threshold is exceeded

False positive for glucose

contamination with cleaning agents

False decreases or negative for glucose

Vit C, ketones, cold urine

What is the most common cause of glucosuria?

hyperglycemia

What can cause hyperglycemic glucosuria?

diabetes mellitus, severe pancreatitis, hyperadrenocorticism, severe stress/excitement, iatrogenic

What can cause normoglycemic glucosuria?

previous transient episode of hyperglycemia, or renal tubular defect

If the normoglycemic glucosuria is due to renal tubular defect what is a cause of this?

gentamycin toxicity

What ketones does the dipstick detect?

acetone and acetoacetate

What ketone is produced in the largest quantity?

B-hydroxybutyrate

When are ketone bodies produced

negative energy balance (starvation or inability to use carbohydrates-lack of insulin)

What can cause false positives for ketones?

pigmented urine

True or false: ketones can be present in urine of healthy animals

false

Which comes first, ketonuria or ketonemia?

ketonuria

True or false: heme in the urine is a very sensitive test

true

Positive heme test in urinalysis could be?

hematuria, hemoglobinuria, myoglobinuria

hematuria

RBCs in sediment, normal plasma color

Hemoglobinuria

red, clean supernatant, no RBCs in sediment, red plasma, evidence of anemia on CBC

myoglobinuria

red brown supernatant, no RBCs in sediment, plasma normal clear, increased CK and AST

True or false: bilirubin can be seen in concentrated urine

true

1+ bilirubin is common in what species?

dogs

Bilirubinuria is always significant in what species?

cats, horses, cattle

positive reaction of urine bilirubin means what?

conjugated bilirubin is in urine

What causes a false decrease in bilirubin

exposure to UV light (keep urine in the dark prior to analysis!)

How many RBCs are considered normal in urine sediment?

<5

How many WBCs are acceptable in urine sediment?

<5

Increased WBCs in urine indicates

pyuria

What is in the urine sediment

wbcs

What is in the urine sediment

rbcs

What is in the urine sediment?

Epithelial Cells

What two ways to collect urine samples may have some bacteria contaminant?

voided and catheterized

What urine collection method should never have bacteria in it?

cystocentesis

True or false: centrifugation of urine concentrates bacteria

false

Struvite crystals

colorless, 3D prism-like crystals, "coffin lids"

True or false: struvite crystals can be seen in urine of healthy animals

true

What are struvite crystals made of?

magnesium ammonium phosphate or triple phosphate

What pH of urine do struvite crystals prefer?

neutral to alkaline

What predisposes the animal to having struvite crystals and urolithiasis?

bacterial cystitis (increases pH)

Amorphous crystals

grain-like precipitate material

Calcium oxalate dihydrate crystals

colorless squares with corners connected by central X

True or false: calcium oxalate dihydrate crystals can be seen in healthy animals

true

What pH can you see calcium oxalate dihydrate crystlas?

any

Where do calcium oxalate dihydrate crystals develop?

in stored urine

Bilirubin crystals

fine needle-like crystallin structure

True or false: bilirubin crystals can be seen normally in concentrated dog urine

true

True or false: bilirubin crystals can be seen normally in cats, horses, and cattle

False, always pathologically significant

Calcium carbonate

large, yellow-brown or colorless spheroids with radial striations or dumbbell shaped

What species is calcium carbonate normal in ?

horses, rabbits, guinea pigs, goats

If you see calcium carbonate in a dog or cat that has signs of renal disease what might it be?

melamine-cyanuric acid crystals (2004 toxic food products outbreak)

What are these?

uric acid crystals

What is this?

ammonium urate/biurate

Urate crystals (both uric acid and ammonium urate/biurate) can be seen when?

portosystemic shunts and other hepatic diseases where hyperammonemia exists

What breeds of dogs get urate crystals?

Dalmatians and English Bulldogs

Calcium oxalate monohydrate

hemp seed, dumbbell shaped or flat, six-sided form (fense pickets)

True or false you can see calcium oxalate monohydrate in health

true

What species would you especially expect to see calcium oxalate monohydrate?

healthy horses and rabbits

What is a pathological cause of calcium oxalate monohydrate?

ethylene glycol poisoning and hypercalciuria (chocolate toxicosis)

Cystine crystals

flat, colorless, hexagonal, with equal or unequal sides. often aggregate in layers

Cystine crystals are seen in what pH of urine?

acidic

What causes some animals to have the tubular inability to reabsorb cystine and cause them to have cystine crystals?

inherited sex linked metabolic abnormality (avoid breeding these animals!)

Casts form where?

distal tubules and collecting ducts

What are casts composed of mainly?

Tamm-Horsefall mucoprotein

Hyaline casts are made of

protein only

Hyaline casts

rounded ends and parallel sides (often cigar shaped)

True or false: some hyaline casts may be seen in healthy animals

true

If you see hyaline casts in high numbers it is associated with

proteinuria (especially glomerular proteinuria)

Epithelial cell casts

desquamation from renal tubules, cast is shed shortly after being formed, cells appear intact

What do epithelial cell casts indicate?

renal disease, ischemia, infarction, nephrotoxicity

True or false: some epithelial cell casts can be seen in a healthy patient

false

What cast is the earliest indicator of renal tubular cell injury when drugs are potentially damaging the kidney?

epithelial cell casts

Granular casts

degenerated cellular casts

True or false: granular casts can be seen in a healthy patient

true

What do large numbers of granular casts indicate?

tubular degeneration consistent with nephritis, nephrotoxin, infection, protein losing nephropathy

Waxy casts

long standing granular casts, with sharp squared off ends, smooth consistency, but more refractile than hyaline casts

What do waxy casts indicate

chronic tubular lesions

True or false waxy casts can be seen in a healthy patient?

false

Waxy casts are often associated with

severe renal disease like glomerulonephritis and amyloidosis

Casts do NOT correlate with of disease

severity

Large number of casts always indicates?

active generalized renal disease

Casts are shed _

intermittently

The lack of casts DOES NOT _ renal disease

rule out