UrinalysisVeterinary Assistant ProgramMiddlesex Community CollegeMichael Lavoie12/17/12

Body Tube

Nosepiece

Objectives

Stage Clips

Light

Ocular lens(Eyepiece)

Arm

Stage

Coarse Adjustment

Fine Adjustment

Always carry a microscope with one hand holding the arm and one hand under the base.

Base

Diaphragm

What’s my power?To calculate the power of magnification, multiply the power of the ocular lens by the power of the objective.

What are the powers of magnification for each of

the objectives we have on our microscopes?

Fill in the table on your worksheet.

Comparing Powers of Magnification

We can see better details with higher the powers of magnification, but we cannot see as much of the image.

Which of these images would be viewed at a

higher power of magnification?

How to make a wet-mount slide …

1 – Get a clean slide and coverslip from your teacher.

2 – Place ONE drop of water in the middle of the slide. Don’t use too much or the water will run off the edge and make a mess!

3 – Place the edge of the cover slip on one side of the water drop.

5 – Place the slide on the stage and view it first with the red-banded objective. Once you see the image, you can rotate the nosepiece to view the slide with the different objectives.

4 - Slowly lower the cover slip on top of the drop.

Cover Slip

Lower slowly

Always carry with 2 handsOnly use lens paper for cleaningDo not force knobsAlways store coveredKeep objects clear of desk and cords

Place the Slide on the Microscope

Use Stage Clips Click Nosepiece to the

lowest (shortest) setting

Look into the EyepieceUse the Coarse Focus

Follow steps to focus using low power

Click the nosepiece to the longest objective

Do NOT use the Coarse Focusing Knob

Use the Fine Focus Knob to bring the slide

Visual Urine Attributes

Volumecolorturbidity

It is ideal to standardize the volume of urine from which the urine sediment is prepared. ◦ In human medicine, 10 ml of urine is used as the

standard volume. This is difficult to accomplish in many animals,

particularly small patients, hence we try and standardize the urine volume from which the urinalysis is performed (regardless of the volume received) to 3 ml

Urine volume affects the results of the urine sediment examination, because the semi-quantitative results of the sediment are derived from the standard urine volume and will differ between urine collections of different volumes.

Observations of color and turbidity are made on the well-mixed urine specimen.

Specific GravityThis is a measure of the urine

concentrating ability of the animal.

The specific gravity should be read on the refractometer using the urine supernatant.

Dip Stick AnaylsisDipsticks consist of various pads

containing chemical ingredients which provide a color change when a particular analyte is present in urine.

This color change is converted to a semi-quantitative result for the analyte in question.

In animals, the dipstick is used to give results for pH, protein, glucose, ketones, bilirubin and proteins containing a heme group (blood)

There are also dipstick pads for urine specific gravity, nitrate, leukocytes and urobilinogen on commercially available dipsticks. ◦These are either not accurate in animals or

do not provide much additional information in animals and are seldom reported.

Sediment ExaminationFor this examination, the

standard volume of urine is centrifuged in a low speed centrifuge.

The supernatant is removed and the urine is gently resuspended in a standard volume (0.5 ml) of urine supernatant.

A drop of the resuspended urine is placed on a slide, coverslipped and examined under a light microscope using the 10x and 40x objectives.

This looks for crystals, bacteria, blood etc.

To examine do the following:

Low MagnificationExamine the entire coverslip

using the 10x objective. ◦At this magnification, casts, large

crystals, debris, parasitic ova are semi-quantified.

High MagnificationSpecific structures identified at

low magnification (e.g. casts) and several random fields are examined using the 40x (high dry) objective.

At this higher magnification, leukocytes, erythrocytes, epithelial cells, fat droplets, small crystals, sperm, debris and bacteria are semi-quantified.

for information on the performance and meaning of the test.

Indications for Urine CollectionDiagnostic, (urinalysis,

radiographic procedures),Therapeutic (urethral blockage,

inability to urinate)

Methods of Collecting Voided SamplesVoided: Easiest method, no special

knowledge or special skill needed.    1) Technique: The urine caught during normal urination in mid-stream in a clean or sterile container.   2) Problems: These samples are considered non-sterile and are often contaminated with bacteria and cells from the lower urinary tract. ◦ If this method is used for an UA (urine

analysis) it should be noted on lab report.

Manual Expression of the BladderThis method is often used in patients unable to

urinate such as neurological and spinal patients.     1) Technique: The patient can be standing, or in lateral recumbency. ◦ One person might need to restrain patient and

another express the bladder depending upon the patient. 

◦ Locate bladder via palpation and apply gentle, steady pressure with hand(s) to push urine out of bladder.

◦ With steady pressure resistance and inhibitory reflexes of sphincter muscles should be overcome.  

Complications 2) Possible problems: Trauma to or

rupture of bladder This method also produces a

"contaminated" sample, usually unsuitable for an accurate UA.

Catheritization1) General information:

          a) This method can be used in both sexes and most species, but is more difficult in females and as the patient gets smaller.         b) It is essential to maintain sterility and avoid iatrogenic infection.          c) Catheters should be lubricated before insertion with sterile gel.        

d) Long hair in the urethral area can be clipped and the urethral area is cleaned with sterile water to avoid contamination        e) The correct size catheter is important to avoid kinking, urine leakage (too small) or causing trauma to the urethra (too large).        f) Pre-measure (estimate) the distance to the bladder. A catheter inserted too far into the bladder can cause trauma and hematuria or even turn on itself and become blocked, or tie itself into a knot, which makes it REALLY hard to remove!

Male Dog CatheterizationInstruments:

◦Sterile plastic semi-flexible catheter or soft red rubber feeding tube and syringe or container to collect urine.   If the catheter is too flexible or too small it

can be difficult to place.

◦Catheter size is expressed in "French" units (Fr), the smaller number indicates a smaller diameter catheter.       

TechniqueTwo or more people may be needed depending on

patient, usually done in standing or lateral position (unless anesthetized).

The assistant exteriorizes the penis and it is gently cleansed with sterile water or very mild disinfectant.

The catheter is handled in a sterile manner (with gloved hands or using the finger tab technique - to be demonstrated in lab).

The catheter tip is lubricated with sterile jelly. The catheter tip is inserted into the penile orifice and is threaded up the urethra into the bladder.

The catheter may be blocked or meet resistance at 2-3 points. If this happens rotate it and increase pressure slightly.

      

Possible problems:Trauma to urethra or lining of

the bladder. Infection if nonsterile catheter is

used.

Indwelling CathetersDepending upon the situation the catheter

may be sutured in place for a period of time to allow the constant drainage of urine and prevent re-blockage.   ◦Usually a UCS (Urinary Collection System) is

usedThese cats should be maintained on a

grate, as they will rapidly soil blankets or towels in their cages. 

In cats do not allow them to use a litter pan, and litter can work its way up the catheter into the bladder.

Female Dog CatheterizationIt is much more difficult to catheterize

females because of the internal position of the urethra, often cystocentesis is the preferred method of collection of a sterile sample for this reason.       a) Equipment: Rigid metal catheter, semi-rigid plastic catheter, Foley catheter, vaginal or nasal speculum, otoscope, etc.     

TechniquesThe bitch is restrained in the standing

position if not under anesthesia, or the catheter can be placed in V/D or D/V position if under anesthesia.

The vulva is cleansed with sterile solution or mild disinfectant and the sterile catheter is handled with gloved hands.

There are several placement techniques: ◦Visual: A speculum (lubricated with sterile gel)

with a light source is used to dilate the vagina and locate the urethral orifice on the ventral surface of the vagina.

Restraint for urine collection and collectionhttp://www.youtube.com/watch?v

=HHFlU0Ry_tY&feature=player_detailpage

http://www.youtube.com/watch?v=mrmEQxUh4YA&feature=player_detailpage

http://www.youtube.com/watch?v=HqRPSXgjaAE&feature=player_detailpage

http://www.youtube.com/watch?feature=player_detailpage&v=ht150ZFT0Ss

Cow Urine Collectionhttp://www.youtube.com/watch?f

eature=player_detailpage&v=lJ__wNhbWn0

Bladder Expressionhttp://www.youtube.com/watch?f

eature=player_detailpage&v=9_9PtTP3PPY

http://www.youtube.com/watch?v=yoYWs6OEfJI&feature=player_detailpage

Urinary SedimentsFormed elements: epithelia, red

cells, white cellsCrystalsMucusRenal castsMicroorganismsSternheimer-Malbin stain

Microscopic UACorrelate with cloudiness and

other findingsQuality control

◦Consistent volume◦Centrifugation◦Well mixed fresh specimen◦Microscopy (wet mount, use low

light)◦Sternheimer-Malbin stain

EpitheliaSquamous epithelia

◦Large flat cell with central oval nucleus

Transitional (bladder) epithelia◦Spindle shaped with large oval

nucleus◦Maybe in sheet

Renal tubular epithelia◦Small cell with large oval nucleus◦Most clinically significant

Squamous Epithelia

Transitional Epithelia

Renal Tubular Epithelia

LeukocytesPus, or pyuriaMay indicate urinary tract

infection UTI if more than 10/HPFGlitter cells in dilute alkaline

urine

Pyuria Bacteriuria

Erythrocytes

Hematuria may indicate renal damage

Menstrual contaminationMay be crenated or ghost cells

Hematuria

Renal CastsCylindruria

◦Renal stasis◦Acidic pH◦Proteinuria◦Concentrated urine

Tamm-Horsfall mucoprotein matrix

Renal CastsHyaline

◦ Least significant◦ Not refractile

Coarse and fine granularCellular

◦ Classified by cells in the castWaxy

◦ End stage renal disease

Hyaline Cast

Fine Granular Casts

Coarse Granular Cast

RBC Casts

WBC Casts

Epithelial Casts

Fatty Cast

Broad Cast

Waxy Casts

MucusUsually of no clinical significance

Common Crystals in Acid pHAmorphous urate

◦Orange powder◦May clear with warming or saline

Uric acid◦Brown lemon shaped or star shaped◦Birefringent with polarized light

Calcium oxalate◦Envelope

Amorphous Urate

Uric Acid

Calcium Oxalate

Common Crystals in Alkaline pHAmorphous phosphate

◦ White powder◦ May clear with saline

Triple phosphate◦ Coffin lid

Ammonium biurate◦ Thorn apple

Calcium carbonate◦ Effervesce with SSA

Amorphous Phosphate

Triple Phosphate

Ammonium Biurate

Calcium Carbonate

QUESTIONS?