URINE ANALYSIS
• It is a very useful indicator of renal
function, and should be performed on any animal suspected to have renal disease or urinary tract pathology
Urinalysis
• A urinalysis consists of gross examination of urine, a specific gravity (SG), chemical
analysis, and sediment evaluation.
• Equipment required : clean glass or plastic collection container, a centrifuge and conical centrifuge tubes, chemical reagent strips, clean glass slides and coverslips, a refractometer and microscope. A sediment stain is recommended.
• The best samples for urinalysis are morning samples. These are the most concentrated.
• Urine samples should be analyzed within 30 minutes to 1 hour of collection.
Routine urine analysis
• Macroscopic investigation
Investigation of physical properties Chemical investigation
• Microscopic analysis
Analysis of urinary sediment
Physical properties of urine
• Color
• volume
• Appearance and transparency(clarity)
• Odor
• Density (specific gravity)
• pH
Urine color
amber sarısı
Pale yellow, green-yellow, uncolored Yellow
Green Red
Pale red-brown Dark brown Milky
Urine volume
24 hours!!!
anuria oligouria poliuria
Normal 24h urine production for dogs and cats is 20-40 ml/kg.
Appereance of the Urine (clarity)
Clear
Turbid-cloudy urates
phosphates or carbonates oxalates
leukocytes bacteria
Urine odor
Urine has a characteristic smell that varies slightly by species and concentration of the sample.
Foul odor -bacteria. Thus, strong smelling urine is common in cases of cystitis.
Acetone- Ketonuria
Urine Density(Specific Gravity)
Hypersthenuria
Urine specific gravity much greater than that of glomerular filtrate (i.e. greater than 1.008 to 1.012). These values are often >1.030 in dogs and >1.035 in cats.
Hyposthenuria
Urine specific gravity that is less than glomerular filtrate (i.e. less than 1.008 to 1.012)
Isosthenuria
Urine specific gravity greater that is similar to glomerular filtrate (i.e. 1.008 to 1.012)
Urine pH
Normal pH is between 6 and 8 for most animals depending on their diet.
A bacterial urinary tract infection with a urease-producing microbe results in alkaluria.
Urine pH affects crystalluria because some crystals, such as struvite, form in alkaline urine, whereas other crystals, such as cystine, form in acidic urine.
Chemical analysis
• Protein
• Glucose
• Ketones
• Blood
• Bilirubin
• Urobilinogen
Protein
• Proteinuria -renal disease.
• Proteinuria
– glomerulonephritis,
– congestive heart failure – renal ischemia
Glucose
Hyperglysemia Diabetes
Excessive endogenous or exogenous glucocorticoids Stress
Urinary ketones
Ketonuria
Primary ketosis (ruminants),
Secondary ketosis to diabetes mellitus (small animals) Diets or ration in low energy
Fasting
Bilirubin
Cholestasis
Biliary obstruction
Secondary to hemolysis
Urobilinogen in the urine
A small amount of urinary urobilinogen is normal.
Increased urinary urobilinogen level occurs in hyperbilirubinemia
A negative test result may be observed with biliary obstruction
Urine nitrates
Gram (-) bacteria
Urinary Sediment
Centrifuge 1500-2000 rpm 3-5 min.
erythrocytes, leukocytes, epithelial cells,
crystals, bacteria, fungi and parasite cells are investigated and examined
Erythrocytes in urinary sediment
hematuria
Leukocytes in urinary sediment
pyuria
Epitheleal cells in urinary sediment
Squamos Epitheleal Cells Renal Epitheleal Cells
Crystals in urinary sediment
• Crystals that can be seen asidic
urine
• Crystals that can be seen alkali
urine
Crystals in acidic urine
Amorphous urate Urate
Calcium oxalate Cystine crystals
Crystals observed in alkali urine
Struvite
Calcium Carbonate
These crystals are common in the urine of normal horses, rabbits, guinea pigs and goats. They have not been observed in canine or feline urine.
Casts
• The presence of increased numbers of casts helps to localize the renal disease to the
tubules, but the numbers to not necessarily correlate with the severity of the disease.
• The five main types of casts are :
Hyaline, Cellular, Granular, Waxy and Fatty
Cast Compilation The image below represents different casts seen in urine at the same magnification and lighting. Shown are hyaline, fatty, granular and waxy casts.
Hyaline casts can be quite difficult to see in wet preparations of urine sediments with light microscopy, even with the condenser of the microscope racked down. They are much easier to visualize using phase contrast, however phase is usually not available on most
microscopes. They become more visible with regular light microscopy if fat sticks to the protein matrix (Tamm-Horsfall mucoprotein) that makes up the hyaline cast (image B) or particulate material from degenerating cells is present within the cast matrix (image C). Cellular casts have distinct cells within the protein matrix - if the cells are of epithelial origin (i.e., not WBCs or RBCs), they are called epithelial casts (images D and E). As cells within the protein cast matrix break down, the cast becomes coarsely (image E and F) then finely granular (image G).
Waxy casts are the final stage of cast degeneration (usually originating from cellular and granular casts). Compared to hyaline casts, they are readily observable because they have a smooth
appearance, no internal texture, and are more refractile than the surrounding urine.
Legend: A: Hyaline cast; B: Fatty cast;
C: Hyaline to finely granular cast; D:
Cellular cast;
E: Cellular to coarsely granular cast; F:
Coarsely granular cast; G: Finely granular cast; H: Granular to waxy cast, I: Waxy cast.
A: Hyaline cast B: Fatty cast
C: Hyaline to finely granular D: Cellular cast;
E: Cellular to coarsely granular
F: Coarsely granular cast;
G: Finely granular cast H: Granular to waxy cast I: Waxy cast.
