Clin Lab III: Urine Sediment ID + Urolithiasis Info.

• Spherical in shape, can appear dull gray or greenish-yellow in color.

• ID’d by characteristic granules or lobulations of the nucleus.

• In concentrated urine, they shrink.

• In diluted urine, they swell.

White Blood Cells.

• In fresh urine, they’re small, round, usually smooth edged, biconcave disc shaped.

• Somewhat refractile.

• Orange or yellow in color, some may be colorless.

• In concentrated urine, they shrink and crenate.

• In dilute or alkaline urine, they swell and may lyse.

Red Blood Cells.

• Largest cells observed in urine sediments.

• Flat, thin cells with a homogeneous appearance and often have straight edges with distinct corners that sometimes curl or fold.

Squamous epithelial cells.

• Usually round, but may appear pear-shaped or caudate (have a tail)

• A low number may be seen due to sloughing of old cells.

• An increased number seen can indicate cystitis or pyelonephritis

Transitional epithelial cells.

• The smallest epithelial cell observed in urine sediment.

• Rarely found, but am increased number seen can indicate renal tubular disease or degeneration/diseases of the kidney parenchyma.

Renal epithelial cells.

• Clear, colorless and somewhat transparent.

• A few seem is normal in urine sediment.

• An increased number seen can indicate the mildest form of renal irritation, as well as fever, poor renal perfusion, strenuous exercise or general anesthesia.

Hyaline Cast.

• The most common type of cast seen in animals.

• A few can be seen in normal urine sediment.

• An increased number seen can indicate acute nephritis, more sever kidney damage than the hyaline cast.

Granular Cast.

• Consist of epithelial cells from the renal tubules imbedded in a hyaline matrix.

• Formed by epithelium sloughing in the tubules.

Epithelial cast.

• Contain WBC’s, predominately neutrophils.

• Their presence indicate inflammation in the renal tubules or pyelonephritis.

WBC cast.

• Form when RBC’s aggregate/clump within the lumen of the tubule.

• Presence indicates renal bleeding.

RBC cast.

• Resemble hyaline casts, but typically wider with square ends.

• Their presence indicates chronic, severe degeneration of the renal tubules.

Waxy casts.

• Contain small droplets of fat.

• More commonly seen in cats due to high lipid content of their tubular epithelium.

Fatty cell cast.

• Typically seen in alkaline urine.

• Resemble “coffin lids”

• Very common urine crystal found in dogs and some cats.

Struvite crystals.

• Seen in alkaline urine.

• Appear as granular precipitate.

Amorphous phosphate crystals.

• Typically seen in alkaline or neutral urine.

• Commonly seen in the urine of horses and rabbits.

• “Dumbbell shape”

• No clinical significance.

Calcium Carbonate crystals.

• Typically seen in slightly acidic, alkaline, or neutral urine.

• Resemble “thorn apples”.

• Commonly seen in animals with severe disease, such as portacaval shunts.

Ammonium biurate crystals.

• Resemble the back of an envelope, or the “xbox” logo.

• Small number is commonly seen in dogs and horses.

Calcium oxalate crystals.

• Small and dumbbell shaped.

• Resemble a slat from a picket fence.

• A large number is seen in animals with ethylene glycol (antifreeze) toxicity.

Calcium Oxalate Monohydrate crystals.

• Seen in animals treated with sulfonamides.

• Less likely to be observed in alkaline urine because they are more soluble in alkaline urine.

Sulfonamide crystals.

• Typically seen in acidic urine.

• Diamond or rhomboid in shape.

• Yellow or yellow-brown.

• Commonly found in dalmations.

Uric acid crystals.

• Typically seen in acidic urine.

• Resemble a wheel or a “pin cushion”.

• Can be seen in animals with liver disease.

Leucine crystals.

• Typically seen in acidic urine.

• Often seen in small clusters.

• Not commonly found in dogs or cats but can be found in animals with liver disease.

Tyrosine crystals.

• Typically seen in a cidic urine.

• Appear flat and 6-sided (hexagonal).

• Can be associated with renal tubular dysfunction or cystine urolithiasis.

Cystine crystals.

• Typically seen in acidic urine

• Appear as rhomboid plates, needles, or granules and are yellow, ruby red, or dark brown in color.

• Commonly seen in conjunction with bilirubinuria and have little to no additional significance.

Bilirubin crystals.

• No clinical significance, normal.

• Can be seen in normal urine samples of dogs.

Cholesterol crystals.

• Can only be identified under the 40x high power objective.

  • May appear to be quivering- Brownian’s movement.

• Large # accompanied by WBC’s can indicate infection/ inflammation of the urinary or genital tract.

Bacteria.

• Often confused with RBC’s or fat droplets.

• Peanut man/footprint shaped.

• Usually considered contaminants when seen in urine sample because this type of infection is rare in animals.

Yeast.

• Filamentous and usually branching.

• These kind of infections are rare, but considered quite serious when they do occur.

Fungi.

• Often confused with casts.

• Resemble a twisted ribbon.

• A large amount is normal in equine.

• In other animals, their presence indicates urethral irritation or contamination of the sample with genital secretions.

Mucus threads.

• Occasionally seen in the sediment of intact male animals or recently bred females.

• A large amount in urine can produce a false positive for protein.

Spermatazoa.

• Seen to some degree in most cats.

• If a prepared urine sediment on a microscope slide sits for a few minutes before being examined, this will rise to a plane of focus just beneath the coverslip.

Fat droplets.

Calculi/stones can cause severe, acute inability to what?

• Urinate or remain in the bladder.

• Can cause inflammation and bleeding.

• Can have blood in their urine.

Most uroliths found in dogs and cats are usually ___________, but oxalate and cystine can also be seen

Struvite.

Removal of uroliths are typically done via a ____________ or urohydropropulsion.

Cystotomy.

How can you prevent uroliths from reoccurring?

• abx therapy (for animals that also have a UTI)

• Special diets

• Increase water consumption

• Possibly other medications to control urine pH.