Urinalysis

Physical Exam of Urine Includes

Volume, color, odor, transparency, specific gravity

Pollakuria

Frequent urination

Polyuria

increased production of urine

Factors involved in urine volume

fluid intake, external losses, temp, humidity, amount/type of food, activity level, size of animal, species

Polyuria often accompanied by ____________

polydipsia

Oliguria

decreased urine output

Anuria

absence of urine production

Normal color of urine

light yellow to amber

Dark yellow urine

more concentrated- higher USG

Lighter colored urine

Less concentrated- lower USG

Yellow-brown or green urine

Contain bile pigments

Red or Brownish Urine

presence of RBCs or hemoglobin

Hematuria

presence of blood in the urine

Hemoglobinuria

hemoglobin in the urine

Normal clarity/transparency of urine in most species

Clear or transparent

Normal equine urine clarity

cloudy

Normal rabbit urine clarity

milky

Classifications of clarity/transparency of urine

clear, slightly cloudy, cloudy, or turbid

A sweet or fruity odor to urine may indicate what?

Presence of ketones

Normal urine specific gravity of dogs

1

Normal urine specific gravity of cats

1

Isosthenuria

When USG approaches that of glomerular filtrate; occurs with chronic renal disease; the closer to the isosthenuria, the more kidney function is lsot

SG of glomerular filtration

1.008-1.012

Storage of chemical reagent strips

Stored at room temp, lid tightly closed

Urine pH

measures the degree of acidity or alkalinity of urine

What can cause decreased urine pH?

Fever, starvation, excessive muscular activity, or certain drugs

What can cause increased urine pH

UTI with urease bacteria, certain drugs, urine retention

Normal urine protein concentration

usually absent or in trace amounts; trace amounts can be found due to collection techniques

Sulfosalicylic Acid Turbidity Test

determine urine protein levels by acid precipitation

Protein/Creatinin ratio

Confirms signifcant amounts of protein and compares to levels of creatinine; aids in accurate measurement of protein loss with low SG

Glucosuria/glycosuria

glucose in the urine

Ketonuria

presence of ketones in the urine

What species is bilirubinuria normal in?

Dogs

In what species is any amount of bilirubin in the urine considered abnormal?

Cats

Ictotest

detects bilirubinuria

Urobilinogen

breakdown product of bilirubin formed by the action of intestinal bacteria; considered normal in urine sample

Myoglobinuria

presence of myoglobin in urine

What is a red color to the supernatant after centrifugation indicative of?

Hemoglobinuria

What causes myoglobinuria?

Severe muscle damage

What centrifuge settings should urine be centrifuged at?

3-5 minutes at 1000-2000 rpm

How should you start evaluating urine sediment on the microscope?

Start under low power to evaluate larger elements, then move to 40x to detect bacteria and differentiate cell types

How are epithelial cells, RBCs, and WBCs reported in urinalysis?

Reported per high power field

How are bacteria reported in urinalysis?

Reported as few, moderate, or many and morphology

Sediment dry mount

Prepared when abnormal cells present; prep similar to blood smear, air dried, stained with diff quick, viewed at 100x

Normal constinuents of urine sedmient

Few casts, crystals, epithelial cells, RBCs and WBCs, mucus threads and sperm, fat droplets

Abnormal constituents of urine sediment

More than a few RBCs and WBCs, hyperplastic or neoplastic epithelial cells, casts, crystals, parasite ova, bacteria, and yeast

Erythrocytes in fresh urine

small, round, smooth edges

Erythrocytes in older concentrated urine

shrunken and crenate

Erythrocytes in dilute urine

Swollen and lyses

Normal amount of erythrocytes in urine

2-3 RBCs/hpf

Urine erythrocytes

Leukocytes in urine

spherical, dull gray or greenish yellow; identified by granules or lobes of nucleus

Pyuria

excessive WBCs in the urine

Urine leukocytes

Increased epithelial cells in urine indicate what?

Inflammation

True or false: A few epithelial cells in urine is considered normal

True

Squamous epithelial cells in urine

Derived from the distal urethra, vagina, vulva, or prepuce; not significant; flat, thin cells with homogenous appearance

Squamous epithelial cell

Transitional epithelial cells in urine

From bladder, ureters, renal pelvis, and proximal urethra; round but occasionalyl pear shaped; small, granular nucleus; low numbers normal;

What do high numbers of transitional epithelial cells in urine indicate?

Cystitis or pyelonephritis; also seen with catheterization

Transitional Epithelial cells

Renal epithelial cells in urine

Smallest epithelial cell; originate in renal tubules; often confused with RBCs; generally round and contain a large nucleus with nongranular cytoplasm; rarely found

What do increased numbers of renal epithelial cells indicate?

Kidney parenchyma

Casts

Formed in the lumen of the distal and collecting tubules of the kidney; classified based on appearance

Hyaline casts

clear and colorless; composed mostly of protein; cylindrical with parallel sides and rounded ends

Granular casts

Hyaline casts with granules; most common type seen

Epithelial casts

consist of epithelial cells from renal tubules embedded in the hyaline matrix

Leukocyte casts

Contain WBCs, mostly neutrophils

Erythrocyte cast

Deep yellow to orange; contain RBCs

Waxy casts

Wider with square ends, dull, homogenous, waxy appearance

Fatty casts

contain small droplets of fat

Cystalluria

presence of crystals

How are crystals reported?

Type and quantity; occasional, moderate, many or 1+-4+

What are struvite crystals also known as?

triple phosphate crystals or magnesium ammonium phosphate crystals

What type of urine are struvite crystals found in?

Alkaline to slightly acidic urine

Struvite crystal

Eight-sided prism with tapered ends; referred to as coffin lids but can take other shapes

Calcium Oxalate Dihydrate Crystals

Small squares with an X across the crystal resembling the back of an envelope; commonly seen in small dogs and horses

What type of urine are Calcium Oxalate Dihydrate crystals found in?

Acidic to neutral urine

Calcium Oxalate Monohydrate Crystals

small dumbbell-shaped or elongated and pointed at each end (picket fence); ethylene glycol poisoning

Urice acid crystals

variety of shapes, yellow or brown; not common except in dalmations

Amorphous Crystalline Material

granular preciptate appearance

Amorphous urates

found in acidic urine

Amorphous phosphates

found in alkaline urine

Calcium Carbonate Crystals

Common in horses and rabbits; round with lines radiating from center or large granular masses or dumbbell shaped

Ammonium Biurate Crystals

brown in color with long, irregular spicules

Sulfonamide Crystals

round, dark with a radiating center

Leucine crystals

Wheel or pincushion, yellow to brown in color

Tyrosine crystals

dark, needlelike projections

Cystine crystals

flat, six-sided, colorless and thin

Pearsonema plica

bladder worm

Dictophyma renale

kidney worm of dogs

Microfilaria immitis

Heartworm

Mucus threads

Resemble a twisted ribbon; often confused with casts; large number in horses

Spermatozoa

sperm cells; often seen with intact males; large numbers can give false-positives for proteins

Fat Droplets in Urine

Lightly green tinged, highly refractile spheres; will rise to surface if set for few moments

Lipuria

fat in urine

Urolithiasis

Formation of stones in the urinary tract.

Most common urinary crystals in dogs and cats

Struvites and calcium oxalate

Most common urolithiasis in dogs and cats

struvite

Caliculi

stones