Interpreting Urinalysis Results Flashcards
Discuss the Gross Appearance of normal urine?
Straw coloured, yellow, clear*, no malodourous smell
Discuss Possible Abnormal results and explanations for abnormal gross appearance of urine?
Colour
Dark: Concentrated
Red: Blood- whole or haemoglobin, beetroot ingestion, drugs e.g. rifampicin
Brown/Green: bile pigments
Brown: Myoglobin
Orange or blue: drug treatments e.g. tetracyclines
Discuss Possible Abnormal results and explanations for abnormal Turbidity (cloudiness) of urine?
Turbidity (cloudiness)
Crystals:*normal in horses and rabbits as excrete calcium in urine*
Cells: urinary tract infection, neoplasia
Discuss Possible Abnormal results and explanations for abnormal Smell of urine?
Smell
Fishy odour: bacterial infection
Sweet: ketones (diabetes mellitus or ketosis)
What should the normal result on urinanalysis for glucose?
No glucose
What are the Possible Abnormal results and explanations for abnormal glucose on urinalysis?
Glucose contamination: if urine collected in contaminated container e.g. jam jar with residue
Glucose present: if renal threshold for glucose is exceeded e.g. diabetes mellitus, very stressed cats, or if renal damage in some types of renal disease allows glucose across into filtrate
Discuss the normal result for bilirubin on urinalysis?
No bilirubin
Discuss the abnormal result for bilirubin on urinalysis?
Positive result may indicate liver disease or haemolysis
Discuss the normal results for ketones on urinalysis?
no ketones
Discuss the abnormal results for ketones on urinalysis?
Positive result recorded with conditions of altered carbohydrate metabolism:
Ketosis in cattle
Pregnancy toxaemia in sheep
Starvation
Diabetes mellitus
Discuss specific gravity on urinalysis?
Ignore on dipstick
Not reliable on dipstick, use refractometer
Discuss normal result for blood on urinalysis?
No blood
Discuss abnormal result for blood on urinalysis?
Haematuria(whole blood): from trauma of collection e.g. cystocentesis, inflammation of the urogenital tract, or contamination in a female in oestrus/proestrus
Haemoglobinuria(free haemoglobin):red cell breakdown e.g. immune mediated haemolytic anaemia,
Myoglobinuria: myoglobin will cause a positive haemoglobin result
Discuss normal pH on urinalysis?
Varies
Herbivores: pH>7
Carnivores: pH<7
Changes in the acid base balance of the body will cause changes in the urine pH
Infection with some bacteria, (Proteus and Staphylococcus sp) will cause alkalinisation
Discuss normal protein on urinalysis?
None or +
Discuss abnormal protein on urinalysis?
False positives: Contamination with alkaline cleaning products, alkaline urine
Positive: Urinary tract infections and inflammation, renal disease such as glomerulonephritis and nephrotic syndrome, multiple myeloma (neoplasia of plasma cells)
Disucss normal Urobilinogen on urinalysis?
Trace normal
Disucss abnormal Urobilinogen on urinalysis?
Not useful or reliable in animals
Positive: Can mean haemolytic disease or liver disease
Discuss normal nitrate on urinalysis?
No nitrite
Discuss abnormal nitrate on urinalysis?
Not valid in animals as false negative results are common as human test strips used
Positive: Can mean bacterial infection
Discuss normal leucocytes on urinalysis?
No leucocytes
Discuss abnormal leucocytes on urinalysis?
Not reliable in animals as false positive results are common as human test strips used
Positive: Can mean urinary tract inflammation or infection
How does the refractometer work?
The refractometer measures the refractive index of the fluid placed in it. It provides an estimate of the solute concentration in the fluid. The urine specific gravity is a measure of how concentrated the urine is, this is affected by how hydrated the animal is and how efficiently its kidneys are functioning.
Discuss normal urine specific gravity ranges for different species?
Dog: (1.001-1.060) – normally 1.015-1.045
Cattle: (1.005-1.040)
Horse: (1.008-1.040 adults 1.001-1.025 foals)
Cats: (1.001-1.080) – normally 1.035-1.060
What is dilute, isothenuric and concentrated in the dog?
For the dog
USG< 1.008 = dilute urine (hyposthenuric)
1.008<usg> 1.012 = <strong>urine that has not been concentrated or diluted</strong> (isothenuric range)</usg>
USG> 1.012 = concentrated urine (hypersthenuric)
What should USG always be interpreted with?
The USG must be interpreted along with the hydration status of the animal to be meaningful. In renal disease the kidneys lose the ability to modify urine and produce urine in the isosthenuric range regardless of the animal’s hydration status.
Discuss urine sediment exam?
Urine Sediment Exam: Normal numbers vary depending on method of sampling
Outline normal erythrocytes on urine sediment exam?
0-3 per high power field (cysto)
Outline abnormal erythrocytes on urine sediment exam?
If unstained, will appear yellow/orange or colourless
Outline normal leucocytes on urine sediment exam?
0-3 per high power field (cysto)
Outline abnormal leucocytes on urine sediment exam?
If unstained, will appear larger than erythrocytes with a grey/yellow colour. Large numbers indicate inflammation or infection
Outline normal epithelial cells on urine sediment exam?
Small numbers are normal
Outline abnormal epithelial cells on urine sediment exam?
Examples include squamous cells(from urethra, vagina, vulva or prepuce), transitional epithelial cells(from bladder, ureter, renal pelvis), or renal epithelial cells(from renal tubules). Large numbers indicate pathology
Discuss the below casts in unrine sediment?
Hyaline
Granular
Cellular
Waxy
Fatty
Small number of hyaline (0-2/hpf)and granular(0-1/hpf) is normal
Formed by protein or cellular deposits in the renal tubules, cylindrical in shape, dissolve in alkaline urine.
Large numbers indicate renal tubule disease
Discuss normal bacteria in urine sediment exam?
No bacteria
Discuss abnormal bacteria in urine sediment exam?
Contamination: free catch or catheterisation samples may be contaminated from the skin, genital tract or lower urinary tract, bacteria also occur in urine that has been stored for any length of time.
Bacterial infection: Commonly E.coli, Proteus, Streptococci spp. If bacteria present in a cystocentesis sample, or if seen with large amounts of leucocytes, then culture and sensitivity testing is required
Leptospira spp. are excreted through the urine but can only be observed using dark field microscopy
Discuss normal struvite in the urine?
Occasionally seen in normal cold, concentrated alkaline urine
How does struvite appear on urine sediment exam?
Struvite aka Magnesium ammonium phosphate
3 to 8 sided prisms, commonly look like coffin lids
Discuss normal Calcium oxalate in urine sediment exam?
Found in acidic or neutral urine, small numbers normal in dogs and horses
what does Calcium oxalate look like?
Dihydrate- small squares with an X shape
Monohydrate- long rectangular or dumbbell shaped
Large numbers indicate ethylene glycol toxicosis
What does normal Calcium Carbonate look like on urine sediment exam?
Normal in horse and rabbit urine
What does calcium carbonate look like?
Round or granular
Discuss Urates/Uric acid in urine sediment exam?
Low numbers may be normal, especially in Dalmatians or English Bulldogs
Seen in acidic urine
What do Urates/Uric acid in urine sediment exam look like?
Urates- yellow/brown coloured spheres, or amorphous structures
Uric acid- diamond shapes
Discuss cystine in urine sediment exam?
Not normal
How does cystine appear in urine sediment exam?
Flat colourless hexagons, presence indicates a genetic defect in renal handling of cystine
Look at these crystals!!!!! Pretty!
