Cross Species - Urinalysis

Question 1

with what other results should you always interpret your USG? what is the purpose of getting a USG?

Answer 1

always with biochemistry panel - assess renal concentrating ability (loss of urine concentrating ability precedes azotemia in patients with renal disease because it starts at approximately 66% decrease in function)

Question 2

what lab results will you look at concurrently with your USG?

Answer 2

age, hydration status, BUN, & creatinine

Question 3

T/F: normal neonates on milk diets have a lower USG

Answer 3

TRUE

Question 4

if the USG of an animal is adequate but is azotemic, what is the classification of the azotemia?

Answer 4

pre-renal

Question 5

low USG with azotemia indicates what?

Answer 5

non-renal causes of PU/PD - diabetes mellitus, HAC

Question 6

what are the normal USG values for dogs, cats, & large animals?

Answer 6

dogs: greater than 1.030, cats: greater than 1.040, & large animals: greater than 1.025

Question 7

what is isosthenuria? what does it indicate?

Answer 7

USG of 1.008-1.012, loss of renal concentrating ability & urine osmolality is similar to plasma - indicates renal tubular dysfunction

Question 8

what is hyposthenuria? what does it indicate?

Answer 8

USG less than 1.008, kidney can dilute urine but not concentrate it either from a lack of response to ADH or renal medullary wash out

Question 9

what diseases do we often see hyposthenuric animals?

Answer 9

diabetes insipidus, primary or secondary to other disease (most common is HAC)

Question 10

when is a urine pH useful?

Answer 10

when assessing sediment & crystalluria

Question 11

grazing animals typically have what type of urine pH? what about carnivores?

Answer 11

grazing: alkaline & carnivores: acidic

Question 12

what are some examples of bacterias that affect urine pH? what do they do to the pH?

Answer 12

streptococcus, ureaplasma, & proteus species

Question 13

T/F: protein in dilute urine is more significant than in concentrated urine

Answer 13

TRUE

Question 14

what is the typical range of protein in the urine from a dipstick?

Answer 14

negative to 3+

Question 15

what should you do if you have a high amount of protein in the urine off of a dipstick?

Answer 15

UPC

Question 16

what values of UPC are considered to be significant in dogs & cats? what should you interept it in light of & why?

Answer 16

dogs: greater than 0.5 & cats: greater than 0.4 - increases with bleeding, inflammation, or infection in the urinary tract, but consider glomerular disease if the sediment is inactive

Question 17

T/F: in animals with multiple myeloma, you will see proteinuria with bence jones proteins which are free light chains of immunoglobulins

Answer 17

TRUE

Question 18

T/F: normal urine does NOT contain glucose

Answer 18

TRUE

Question 19

if there is glucose in the urine, what does that indicate?

Answer 19

renal threshold has been exceeded

Question 20

T/F: transient stress hyperglycemia in cats & cattle can cause glucosuria

Answer 20

TRUE

Question 21

in an animal with fanconi syndrome, what would you expect their glucose in their blood & urine to be? why?

Answer 21

normal blood BG & glucose in urine - seen with renal tubular defect

Question 22

ketones on a dipstick mainly detects what type?

Answer 22

acetoacetic acid

Question 23

what does ketonuria indicate? what are some examples of diseases in dogs/cats, sheep, & cattle where this may be seen?

Answer 23

abnormal energy metabolism (negative energy balance - fat used for energy instead of glucose), dogs & cats - unregulated diabetes, sheep - pregnancy toxemia, & cattle - bovine ketosis type I

Question 24

T/F: for dogs only, a low level of bilirubin in the urine is normal

Answer 24

TRUE

Question 25

T/F: bilirubin will increase in the urine before it increases in the serum in an animal with cholestasis

Answer 25

TRUE

Question 26

is heme on a dipstick specific? what does it detect?

Answer 26

nope - detects free hemoglobin (secondary to intravascular hemolysis), myoglobin (secondary to rhabdomyolysis), & hematuria

Question 27

how do you differentiate causes of pigmenturia?

Answer 27

centrifuge urine samples - blood sediments out while hemoglobin/myoglobin doesn't

Question 28

for cellular constituents of urine looked at microscopically, how are they counted?

Answer 28

counted per high powered field

Question 29

why may you have increased red blood cells when doing a microscopic examination of urine?

Answer 29

influenced by collection method (low numbers in cystocentesis), contamination from genital tract if free catch samples (post-partum, estrus, & BPH in male dogs)

Question 30

how may a UTI influence what you see microscopically of the urine?

Answer 30

pyuria with UTI - increased WBC & bacteria (if isothenuric, bacteria may not be seen), or pyuria with hematuria - increased WBC in conjunction with increased RBC where there are more RBC than WBC

Question 31

what kind of cells can exfoliate into the urine? what does that indicate?

Answer 31

neoplastic epithelial cells - TCC

Question 32

T/F: you can see sperm in the urine from healthy intact males

Answer 32

TRUE

Question 33

if you see crystals in urine microscopically, what does that indicate?

Answer 33

urine supersaturation with minerals involved in crystal formation

Question 34

what different diseases can crystalluria indicate?

Answer 34

urinary tract disease (struvite, aka magnesium ammonium phosphate crystals, in small animals with bacterial UTIs), metabolic disease (ammonium biurate crystals in dogs with PSS)

Question 35

what is different for horses & urinary crystals?

Answer 35

normal horses can have high levels of calcium crystals

Question 36

what are patient factors that can influence urine crystal formation? what are some in vitro factors?

Answer 36

supersaturation of urine with crystallogenic substances, diet, & urine pH - storage temperatures & pH

Question 37

does crystal type represent urolith type? why?

Answer 37

nope - can see struvite crystals in a dog with calcium oxalte urolithiasis & concurrent bacterial UTI

Question 38

what is the most common urinary crystal found in dogs & cats? what does it look like? when are they seen?

Answer 38

struvite, coffin lid shape that forms in neutral to alkaline urine - increased incidence with urease-producing bacterial UTIs because infection increases urine pH & liberates ammonium

Question 39

what do calcium oxalate dihydrate crystals look like? how do they form?

Answer 39

envelope shape, can form at any pH - can develop spontaneously in stored urine, so interpret with caution

Question 40

calcium oxalate monohydrate crystals are specific for what disease in small animals? what do they look like? what do they indicate? what animal may they appear normally in?

Answer 40

ethylene glycol toxicity (crystals with picket fence) - in others, dumb bell/spindle shape or oval shaped that form due to super saturation with calcium & oxalate (can be seen in normal horse urine)

Question 41

what do bilirubin crystals in the urine look like? what animals are they seen in?

Answer 41

needle to granular like yellow color that form in normal to highly concentrated urine - seen in animals with cholestasis

Question 42

what animals commonly get calcium carbonate urinary crystals? what do they look like? what animals don't get them?

Answer 42

normal horse, rabbits, guinea pigs, & goats (large sphere with radial striations) - not seen in dogs & cats

Question 43

what do ammonium biurate urinary crystals look like? what animals are they seen in & why?

Answer 43

brown to yell spheres with irregular protrusions that form in neutral to acidic urine - animals with congenital or acquired portal vascular anomalies & also seen in urine of normal dalmatians & english bulldogs (both are predisposed to urolithiasis)

Question 44

what do cysteine urinary crystals look like? when are they seen & why?

Answer 44

hexagon shape, form in acidic urine - indicative of inborn error of metabolism, almost always intact male dogs

Question 45

what are urinary casts? what do they mean clinically?

Answer 45

cynlindrical appearance of mucoproteins that are secreted by renal tubular epithelial cells that can indicate renal tubular damage (acute kidney injury)

Question 46

what type of urinary cast can be seen in healthy animals with concentrated urine?

Answer 46

hyaline

Question 47

cellular urinary casts are most commonly seen with what disease processes? what does it indicate?

Answer 47

renal ischemia, infarction, & nephrotoxicity - acute tubular injury

Question 48

what are granular casts? when are they seen?

Answer 48

degeneration of cellular casts - form for the same reasons as cellular casts

Question 49

what are waxy urinary casts? what do they indicate?

Answer 49

final stage of cellular cast degredation, indicates more chronic tubular injury

Question 50

T/F: normal urine is sterile

Answer 50

TRUE

Question 51

T/F: voided urinary samples can have a low number of bacteria from lower urinary tract contamination

Answer 51

TRUE

Question 52

patients with diabetes mellitus can have clinically significant bacteriuria without pyuria, why?

Answer 52

they are immunosuppressed

Question 53

if a patient you collected urine from with either a sterile catheterization or cystocentesis, the urine should or should not have contamination?

Answer 53

none - if any is seen, significant

Question 54

what fungal element is often seen in urine that indicates infection in immunosuppressed patients?

Answer 54

yeast