A urinalysis involves checking the physical characteristics of urine, performing a chemical analysis using a dipstick, and examining the urine sediment under a microscope. The dipstick tests for various substances like protein, glucose, ketones, blood, and nitrites that may indicate underlying health issues. Examining the urine sediment provides additional information by revealing cells, casts, crystals, bacteria, and lipids that can help diagnose urinary tract infections or kidney problems. Interpreting the results of a urinalysis requires considering factors like an animal's medical history and current medications.

1. Performing the Urinalysis
Laboratory Procedures

2. Analyzing the Urine Sample
 A complete urinalysis usually involves
3 steps.
 1. Checking and recording the physical
characteristics of the urine
 2. Performing a chemical analysis using a
multi-test dipstick
 3. Centrifuging a small portion of the
sample and examining the sediment
under a microscope

3. 1. Checking and recording the
physical properties of the urine
 Physical properties include:
 Color
 Transparency
 Odor
 Specific gravity
 Volume

4. 2. Chemical Analysis
 Many chemical tests can be performed on a small
quantity of urine by using a dipstick
 Each pad on dipstick is designed to test for a
particular substance in the urine.
 When the urine comes in contacts with the reagents,
a chemical reaction will cause a color change based
on the amount of the substance in the urine.
 Color is compared to chart, and approximate amount
of substance in urine can be determined

5.  Several brands of dipstick exist.

7. Chemical analysis
 Certain drugs and medications may
interfere with chemical tests.
 Be sure to know any medications
animal is currently receiving when
performing a urinalysis.

8. Components on the Dipstick
 Urine pH
 Protein
 Glucose
 Ketones
 Bilirubin
 Urobilinogen
 Blood
 Nitrites

9. Urine pH
 Number of how acidic or alkaline the urine is
 pH is affected by diet.
 Plant diets can cause alkaline urine
 High protein diets can cause acidic urine
 Small animal pH is usually acidic
 In general dog and cat urine pH is 6-7
 Large animal urine is usually alkaline
 Other factors may affect urine pH
 Fever
 Starvation
 Certain drugs

10. Protein
 Healthy animals will usually not have any
protein in their urine although in some
cases trace amounts can be found in
concentrated dog and cat urine.
 The urine protein level must be interpreted
along with the Urine specific gravity.
 Small amounts of protein are more
significant in dilute or unconcentrated
urine.
 Protein may be lost in the urine due to
glomerulopathies, inflammation, or
hemorrhage.

12. Glucose
 If the sugar in the blood is
significantly higher than normal,
some excess may be found in the
urine.
 Normal dog and cat urine should be
negative for glucose.
 In some cases if the urine is not run
immediately, false glucose readings
may occur.

13. Ketones
 Ketones are the substances formed in the
body during the breakdown of lipids.
 Normal pet urine should be negative for
ketones
 When excess amounts of ketones are
formed, their levels rise in the blood and
then are released in the urine.
 Can cause CNS depression and acidosis
 May result in ketonuria caused by:
 Starvation
 Diabetes

14. Bilirubin
 Pigment made by the liver from dead or
dying red blood cells.
 Small amounts may sometimes be found in
healthy dogs.
 Dogs can conjugate bilirubin in their kidneys, so
small amount may be insignificant.
 Bilirubin found in cat urine is a concern and
can be a sign of liver disease, bile duct
obstruction, or hemolysis.

15. Urobilinogen
 Compound formed from bilirubin by
intestinal tract.
 Normal dogs and cats have small amounts
of urobilinogen in their urine.
 Results from dipstick are not considered
very accurate and may be difficult to
interpret.
 Usually recorded as “normal” or
“abnormal”.

16. Blood
 Healthy pets may have a
few red blood cells in their
urine, but greater than ~5
cells per field may indicate
a problem.
 Hematuria can be due to a
number of causes:
 Trauma
 Urinary Tract Infection (UTI)
 Bladder Stones
 Blood Clotting Problems

17. Blood cells in the Urine

18. Nitrites
 May be produced by the bacteria
present in some infections
 Test often shows a “false negative”
and is considered inaccurate in pets.
 However, if positive, should examine
sediment closely for bacteria.

19. Examining Urine Sediment
 After urine sediment is centrifuged
(generally about 5 minutes), the top
portion of the liquid is poured off and the
sediment is resuspended and examined
microsopically.
 Indications for sediment exam include:
 Provides additional information
 A form of cytology
 Must be interpreted with other clinical data,
including physical and chemical composition of
the urine.

20. Urine Sediment Exam Procedure
 1. Collect urine in a clean container
 2. Throughly mix specimen and transfer 3-
5 ml volume to a centrifuge tube
 3. Centrifuge for 3-5 mins
 4. Pour off supernatant
 5. Leave approximately 0.5 ml of
supernatant
 6. Resuspend urine sediment by tapping
tube or flicking it w/ your finger.
 7. Examine a stained or unstained
sediment. (Or both!)

21. Potential Sediment Elements
 White blood cells
 Red blood cells
 Lipid droplets
 Bacteria
 Crystal
 Casts

22. White blood cells
 Larger than normal numbers of white
blood cells may indicate inflammation
from a bladder or kidney infection.

23. Lipid Droplets
 Are common in the sediment of urine,
especially in cats.
 Number and size may vary
 Should not be confused w/ air
bubbles or RBC’s. They will be in
focus when other structures are
not.

24. Bacteria
 Sediment is examined for presence of
bacteria
 Small amounts may be due to
contamination, large amounts may
indicate bladder infection (especially
if sample is obtained via
cystocentesis).
 A urine culture and sensitivity may
indicated with large amounts of
bacteria.

26. Crystals
 Made up of minerals and can
sometimes be found in the urine.
 Under certain conditions, crystals can
clump together to form bladder
stones (uroliths).
 The pH of the urine may influence the
type of crystal development
 Some animals and species are more
predisposed to crystal and stone
formation.

27. Common Crystal
Types
 Struvite
 Calcium Oxalate
 Ammonium Urate

28. Casts
(These will be covered in depth in Clin-Path!)
 Urine Casts are small cylinder-shaped formations of
cells and debris from inside the tubules of the kidneys
 Presence and composition of casts can indicate kidney
function
 Types of casts:
 Hyaline
 Granular
 Waxy
 Fatty
 Cellular
 Mixed
 Bile stained

29. Specific Gravity
 Measures the concentrating ability of the
kidney.
 Done with a refractometer
 There may be a spot on the dip-stick
for SG, however in animals, these are
not valid results.

30. Specific Gravity “normals” p. 158 Lab bk
 “Normal” values in dogs is between 1.001-1.060
 “Normal” values in cats can range from 1.001 – 1.080
 There is no set “normal” value in animals, however the
following guidelines should be used:
 SG: below 1.008 is said to indicate dilution (hyposthenuric)
 SG: 1.008-1.012 is said to be fixed or isosthenuric (same SG as
plasma)
 SG: 1.013 – 1.030 is considered normal if no dehydration
suspected.
 SG: above 1.025 implies renal tubule concentration ( in cats, this
can indicate renal disease)