Cross Species - Urinalysis Flashcards
with what other results should you always interpret your USG? what is the purpose of getting a USG?
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)
what lab results will you look at concurrently with your USG?
age, hydration status, BUN, & creatinine
T/F: normal neonates on milk diets have a lower USG
TRUE
if the USG of an animal is adequate but is azotemic, what is the classification of the azotemia?
pre-renal
low USG with azotemia indicates what?
non-renal causes of PU/PD - diabetes mellitus, HAC
what are the normal USG values for dogs, cats, & large animals?
dogs: greater than 1.030, cats: greater than 1.040, & large animals: greater than 1.025
what is isosthenuria? what does it indicate?
USG of 1.008-1.012, loss of renal concentrating ability & urine osmolality is similar to plasma - indicates renal tubular dysfunction
what is hyposthenuria? what does it indicate?
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
what diseases do we often see hyposthenuric animals?
diabetes insipidus, primary or secondary to other disease (most common is HAC)
when is a urine pH useful?
when assessing sediment & crystalluria
grazing animals typically have what type of urine pH? what about carnivores?
grazing: alkaline & carnivores: acidic
what are some examples of bacterias that affect urine pH? what do they do to the pH?
streptococcus, ureaplasma, & proteus species
T/F: protein in dilute urine is more significant than in concentrated urine
TRUE
what is the typical range of protein in the urine from a dipstick?
negative to 3+
what should you do if you have a high amount of protein in the urine off of a dipstick?
UPC
what values of UPC are considered to be significant in dogs & cats? what should you interept it in light of & why?
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
T/F: in animals with multiple myeloma, you will see proteinuria with bence jones proteins which are free light chains of immunoglobulins
TRUE
T/F: normal urine does NOT contain glucose
TRUE
if there is glucose in the urine, what does that indicate?
renal threshold has been exceeded
T/F: transient stress hyperglycemia in cats & cattle can cause glucosuria
TRUE
in an animal with fanconi syndrome, what would you expect their glucose in their blood & urine to be? why?
normal blood BG & glucose in urine - seen with renal tubular defect
ketones on a dipstick mainly detects what type?
acetoacetic acid
what does ketonuria indicate? what are some examples of diseases in dogs/cats, sheep, & cattle where this may be seen?
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
T/F: for dogs only, a low level of bilirubin in the urine is normal
TRUE
T/F: bilirubin will increase in the urine before it increases in the serum in an animal with cholestasis
TRUE
is heme on a dipstick specific? what does it detect?
nope - detects free hemoglobin (secondary to intravascular hemolysis), myoglobin (secondary to rhabdomyolysis), & hematuria
how do you differentiate causes of pigmenturia?
centrifuge urine samples - blood sediments out while hemoglobin/myoglobin doesn’t
for cellular constituents of urine looked at microscopically, how are they counted?
counted per high powered field
why may you have increased red blood cells when doing a microscopic examination of urine?
influenced by collection method (low numbers in cystocentesis), contamination from genital tract if free catch samples (post-partum, estrus, & BPH in male dogs)
how may a UTI influence what you see microscopically of the urine?
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
what kind of cells can exfoliate into the urine? what does that indicate?
neoplastic epithelial cells - TCC
T/F: you can see sperm in the urine from healthy intact males
TRUE
if you see crystals in urine microscopically, what does that indicate?
urine supersaturation with minerals involved in crystal formation
what different diseases can crystalluria indicate?
urinary tract disease (struvite, aka magnesium ammonium phosphate crystals, in small animals with bacterial UTIs), metabolic disease (ammonium biurate crystals in dogs with PSS)
what is different for horses & urinary crystals?
normal horses can have high levels of calcium crystals
what are patient factors that can influence urine crystal formation? what are some in vitro factors?
supersaturation of urine with crystallogenic substances, diet, & urine pH - storage temperatures & pH
does crystal type represent urolith type? why?
nope - can see struvite crystals in a dog with calcium oxalte urolithiasis & concurrent bacterial UTI
what is the most common urinary crystal found in dogs & cats? what does it look like? when are they seen?
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
what do calcium oxalate dihydrate crystals look like? how do they form?
envelope shape, can form at any pH - can develop spontaneously in stored urine, so interpret with caution
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?
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)
what do bilirubin crystals in the urine look like? what animals are they seen in?
needle to granular like yellow color that form in normal to highly concentrated urine - seen in animals with cholestasis
what animals commonly get calcium carbonate urinary crystals? what do they look like? what animals don’t get them?
normal horse, rabbits, guinea pigs, & goats (large sphere with radial striations) - not seen in dogs & cats
what do ammonium biurate urinary crystals look like? what animals are they seen in & why?
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)
what do cysteine urinary crystals look like? when are they seen & why?
hexagon shape, form in acidic urine - indicative of inborn error of metabolism, almost always intact male dogs
what are urinary casts? what do they mean clinically?
cynlindrical appearance of mucoproteins that are secreted by renal tubular epithelial cells that can indicate renal tubular damage (acute kidney injury)
what type of urinary cast can be seen in healthy animals with concentrated urine?
hyaline
cellular urinary casts are most commonly seen with what disease processes? what does it indicate?
renal ischemia, infarction, & nephrotoxicity - acute tubular injury
what are granular casts? when are they seen?
degeneration of cellular casts - form for the same reasons as cellular casts
what are waxy urinary casts? what do they indicate?
final stage of cellular cast degredation, indicates more chronic tubular injury
T/F: normal urine is sterile
TRUE
T/F: voided urinary samples can have a low number of bacteria from lower urinary tract contamination
TRUE
patients with diabetes mellitus can have clinically significant bacteriuria without pyuria, why?
they are immunosuppressed
if a patient you collected urine from with either a sterile catheterization or cystocentesis, the urine should or should not have contamination?
none - if any is seen, significant
what fungal element is often seen in urine that indicates infection in immunosuppressed patients?
yeast
