Urinalysis Flashcards
Urine turbidity means
cloudiness, is subjective
Evaluated as: Clear, slightly cloudy, cloudy, opaque
Cloudiness is caused by:
Elevated RBC and WBC
Bacteria
Crystals
Semen
Strong smell to urine can indicate
Strong smell of ammonia – can indicate bacteriuria.
An acetone smell to urine can indicate
ketoacidosis
Urine special gravity (USG) Measures
the solute concentration in urine
Urine special gravity (USG) is used to assess
the tubular function of the kidneys and the kidneys ability to concentrate urine.
Ability to concentrate urine decreases when 2/3 of the tubules are damaged.
Normal USG
Dogs
Cats
Dogs 1.015 – 1.045
Cats 1.035 – 1.060
Using urine Concentration (USG) in evaluation of kidney function with azotemia.
Isosthenuria =
USG same as in plasma (1.008 – 1.012)
Usually happens with Renal azotemia – kidneys can’t concentrate nor dilute urine.
Hyposthenuria
USG ＜1.008
Kidneys CAN dilute urine
But they can’t CONCENTRATE urine (aka remove excess water) – ADH deficiency (diabetes insipidus).
Most common chemical parameters measured from urine: (6)
Inaccurate or unimportant parameters, but are included on dipsticks: (4)
pH, protein, glucose, ketones, bilirubin, heme
Inaccurate or unimportant parameters, but are included on dipsticks: leukocytes, USG, nitrites, urobilinogen.
Cats and dogs urine pH
Cats and dogs – acidic urine (pH 5,5 – 7,0)
Urine pH can be affected by (5)
Acid-base balance
Pathological changes in kidney tubules
Bacteria in urine
Diet
Temperature
Struvite crystals are usually found in what pH urine?
And Oxalate?
Struvite in alkaline urine
Oxalate in acidic urine
Glucosuria – glucose appears in urine when?
when dog & cat mmol/L?
when blood glucose levels exceed the renal threshold of glucose reabsorption.
when BG dogs 9,9 mmol/l
when BG cats 16,5 mmol/l
Always evaluate the blood glucose levels as well. Caused by Diabetes mellitus, Addison’s, acromegaly, kidney diseases, stress (cats)
Describe Proteinuria
Mainly ALB
Small amount can be normal (dehydrated animals).
Describe UPC.
urine protein and creatinine ratio
More accurate evaluation of proteinuria for renal causes.
Measured from the supernatant (sediment spun and segregated, skim supernatant off top).
Have to exclude pre- and post-renal causes.
Normal UPC＜0,5
Abnormal UPC >1,0
Name Pre-renal causes of proteinuria. (2)
hemoglobinuria,
myoglobinuria (transient)
Name 2 renal causes of proteinuria.
protein losing nephropathy (PLN), glomerular diseases.
Name post-renal causes of proteinuria. (2)
blood contamination,
bacteria.
What ketones are commonly measured from urine? (2)
Acetoacetate, acetone
(Does not measure alpha-hydroxybutyrate)
Ketonuria appears before ketonemia
Dipstick can be used to measure ketones in plasma/serum as well.
Ketonuria is caused by
negative energy balance, fat is being used instead of glucose and thus ketones.
Diabetic ketoacidosis, unregulated diabetes.
Malnutrition, carbohydrate-poor diet.
Constant hypoglycemia.
BLD on dipsticks, measures what exactly?
Heme which is in both hemoglobin and myoglobin.
Heme in urine can be (origin): (3)
- Hematuria (RBC) – confirm with microscope.
- Intravascular hemolysis (hemoglobin)
- Muscle damage (myoglobin)
How can you tell the difference between Hemo-/myoglobinuria vs hematuria?
When centrifuged, in hemo- & myoglobinuria, the urine stays red/brown.
In hematuria, the urine goes clear, erythrocytes segregate to the sediment.
Other helpful tips:
- Hb makes the plasma red.
- Myoglobin also elevates CK and AST in blood.
