Urinalysis Unit 5 Chapter 29 Urine Sediment Analysis Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved.

Microscopic Examination Important part of a complete urinalysis Many abnormalities cannot be detected by the reagent test strip More specific information obtained In humans – only done when patients are symptomatic or abnormalities are evident In animals – every urinalysis Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 2

Sediment The urine of most domestic animals does not contain a high level of sediment May find the following in most species Epithelial cells Mucus threads RBCs WBCs Hyaline casts Crystals Exceptions – horses and rabbits Large amounts of calcium carbonate Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 3

Sediment (cont.) Best samples First morning collection or after hours of water deprivation Highly concentrated urine Examine fresh Changes occur if allowed to set at room temperature Casts dissolve Crystals form Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 4

Sediment (cont.) Volume of urine collected and volume of sediment recorded 5 to 10 ml ideal Centrifuge 3 to 5 minutes at 1000 to 2000 rpm Excessive force may distort or disrupt elements Supernatant poured off, leaving approximately 0.5 ml of urine at bottom of tube Resuspend by gently flicking with finger to mix Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 5

Kova Urine Sediment System Unique system provides an even distribution of elements Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 6

Sediment (cont.) Examined stained or unstained A small drop on a slide covered with a coverslip Subdued light to refract elements Partially close diaphragm and adjust condenser down Continuously adjust fine knob to see depth of objects Stain may help identify cell types Can introduce artifacts 0.5% new methylene blue Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 7

Sediment (cont.) One drop of stain mixed with sediment before placing on microscope slide – coverslip Can have stained and unstained side by side Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 8

Sediment (cont.) Start under low power Evaluate larger elements Casts or aggregates of cells Reported as number observed per low power field (LPF) Move to x40 Detect bacteria, differentiate cell types Epithelial cells, RBCs, WBCs Reported as #/hpf Bacteria Reported as few, moderate, or many and morphology Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 9

Constituents of Urine Sediment Normal may have a few casts, crystals, epithelial cells, RBCs and WBCs, mucus threads and sperm (males), and fat droplets Abnormal More then a few RBCs and WBCs, hyperplastic or neoplastic epithelial cells, casts, crystals, parasite ova, bacteria, and yeast Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 10

Cell Types in Urine Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 11

Erythrocytes May have different appearances depending upon urine concentration, pH, and time elapsed from collection Fresh – small, round, smooth edges Older – concentrated Shrink and crenate Dilute Swell and lyse Normal 2 to 3 RBCs/hpf Presence indicate bleeding somewhere in the urinary tract Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 12

Erythrocytes (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 13

Leukocytes Larger than RBCs and smaller then renal epithelial cells Spherical, dull gray or greenish yellow Identified by granules or lobes of nucleus Pyuria – excessive WBCs in the urine Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 14

Epithelial Cells A few are normal Increased Inflammation Three types Squamous Transitional Renal Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 15

Squamous Epithelial Cells Derived from the distal urethra, vagina, vulva, or prepuce Not considered significant Flat, thin cells with homogeneous appearance Largest cells in urine Straight edges with distinct corners Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 16

Transitional Epithelial Cells From bladder, ureters, renal pelvis, and proximal urethra Round but occasionally pear shaped Small, granular nucleus Low numbers are normal High numbers indicate cystitis or pyelonephritis or in cases of catheterization Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 17

Epithelial Cells (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 18

Renal Epithelial Cells Smallest epithelial cell Originate in renal tubules Often confused with WBCs Generally round and contain a large nucleus with nongranular cytoplasm Rarely found Increased numbers Kidney parenchyma Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 19

Casts Formed in the lumen of the distal and collecting tubules of the kidney Secreted protein precipitates in acidic conditions and forms casts shaped like the tubules Classified based on appearance Hyaline, epithelial, cellular, granular, waxy, fatty, and mixed casts Type depends on how quickly the filtrate moves through the tubules Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 20

Casts (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 21

Casts (cont.) Hyaline Clear and colorless Composed of mostly protein Cylindrical with parallel sides and rounded ends Increased with fever, poor renal fusion, exercise, or general anesthesia Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 22

Casts (cont.) Granular casts Hyaline casts with granules Most common type seen Acute nephritis Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 23

Casts (cont.) Epithelial casts Consist of epithelial cells from the renal tubules embedded in the hyaline matrix Acute nephritis and degeneration of the renal tubular epithelium Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 24

Casts (cont.) Leukocyte casts Contain WBCs, mostly neutrophils Inflammation in renal tubules Erythrocyte casts Deep yellow to orange Contain RBCs Indicate renal bleeding Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 25

Casts (cont.) Waxy casts Wider with square ends, dull, homogeneous, waxy appearance Fatty casts Contain small droplets of fat Seen in cats with renal disease Occasionally in dogs with diabetes mellitus Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 26

Crystals Crystalluria – presence of crystals May or may not be clinically significant Crystals form as a result of elements being secreted by normal renal activity Some crystals are indicative of metabolic disease May lead to urinary calculi Dependent upon urine pH, concentration, temperature, and elements Reported as: Type and quantity Occasional, moderate, many or 1+ to 4+ Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 27

Types of Crystals Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 28

Struvite AKA – triple phosphate crystals or magnesium ammonium phosphate crystals Found in alkaline to slightly acidic urine Eight-sided prisms with tapered ends Referred to as coffin lids but may take other shapes such as a fern leaf; high concentration of ammonia in urine Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 29

Struvite (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 30

Calcium Oxalate Dihydrate Small squares with an X across the crystal resembling the back of an envelope Found in acidic to neutral urine Common in small dogs and horses Monohydrate Small, dumbbell shaped or elongated and pointed at each end (picket fence) Ethylene glycol poisoning Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 31

Calcium Oxalate (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 32

Uric Acid A variety of shapes but usually diamond or rhomboid Yellow or yellow brown Not common in dogs or cats except dalmatians Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 33

Amorphous Crystalline Material Common in alkaline urine Granular precipitate appearance Amorphous urates – acidic urine Amorphous phosphates – alkaline urine Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 34

Calcium Carbonate Common in horses and rabbits Round with lines radiating from center or large granular masses or dumbbell shaped No clinical significance Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 35

Ammonium Biurate Seen in slightly acidic, neutral, or alkaline urine Brown in color with long, irregular spicules Common in animals with severe liver disease – portacaval shunts Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 36

Sulfonamide Seen in animals treated with sulfonamides Round, dark with a radiating center Prevention Encouraging water consumption Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 37

Other Crystals Leucine Wheel or pincushion, yellow to brown in color Liver disease Tyrosine Dark, needlelike projections Liver disease – not common in dogs or cats Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 38

Other Crystals (cont.) Cystine Flat, six sided, colorless, and thin Renal tubular dysfunction or cystine urolithiasis Associated with melamine toxicity Golden brown, round to oval with radial striations Present in animals fed diets with melamine or cyanuric acid Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 39

Microorganisms Bacteria Proliferate if urine is left standing Identified only under magnification Cocci or bacilli Reported as few, moderate, many, or TNTC Indicative of infection and inflammation Culture Yeasts May be confused with fat droplets Budding Rare in domestic animals Fungi Filamentous and branching Uncommon but serious if occur Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 40

Parasite Ova and Microfilaria Fecal contamination at time of collection Parasite of the urinary tract Pearsonema plica – bladder worm Dictophyma renale – kidney worm of dogs Microfilaria immitis – adult heartworms Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 41

Miscellaneous Components of Urine Mucus threads Confused with casts Resemble twisted ribbon Large number in horses In other animals indicates urethral irritation or contamination with genital secretions Spermatozoa Intact males Large numbers can give false-positives for protein Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 42

Miscellaneous Components of Urine (cont.) Fat droplets Lightly green-tinged, highly refractile spheres Will rise to surface if set for few moments Different plane of focus Lipuria – fat in urine Cats – obesity, diabetes mellitus, hypothyroidism, and high- fat meals Artifacts Enter during collection, transport, or examination Air bubbles, oil droplets, hair, feces, pollen, dust, etc. Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 43

Urolithiasis Calculi (stones) May cause blockages or remain in bladder Must determine composition Patient prognosis and prevention Then initiate treatment to remove them Common in castrated male ruminants Sheep, goats, and steers Analysis at reference laboratories Dogs and cats usually struvite but other can be observed Dalmatians – urate uroliths Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 44

Summary Subdued lighting on microscopic examinations Start at low magnification and move to x40 Identify RBCs WBCs Casts Crystals Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 45