PRACTICAL: Clinical pathology and urinary tract infections Flashcards
What should you examine urine for before spinning?
APPEARANCE:
- turbidity
- colour
- odor
Name 3 parts of urine examination
- gross appearance
- chemical analysis
- sediment analysis
What does sediment analysis include?
- cellular elements
- crystals
- casts
- others
What is urine pH?
- influenced by diet
- lower with high protein diets and fasting in herbivores
- higher pH with vegetable diet
- fresh sample essential (becomes alkaline on standing)
Why does cystitis have a higher pH?
d/t conversion of urea to ammonia by bacteria
T/F: pH may determine types of crystals formed
True
4 types of proteinuria
- prerenal
- glomerular
- tubular
- haemorrhagi or inflammatory proteinuria (postrenal)
When does glucose overspill occur?
- > 9mmol/L in dogs
- >14 mmol/L in cats
What are the 2 types of glucosuria?
- hyperglycemic glucosuria (DM)
- renal glucosuria
What do ketones suggest?
excessive fat degeneration (rather than using glucose as an energy source)
What are the ketone bodies?
- acetoacetate (reagent strip primarily detects this)
- beta-hydroxybutyrate
- acetone
When do you get ketonuria?
- poorly controlled diabetes
- starvation
Causes - bilirubin in the urine
- when there are increased amounts:
- haemolytic anaemia
- liver disease with cholestasis
- gall bladder or bile duct obstruction
Is the threshold for urine bilirubin higher or lower in cats or dogs? Importance?
lower in dogs: small amount (especially male) dogs not concerning, always significant in cats
Appearance of urine with bilirubin
may appear bright yellow and stain surfaces
Define haematuria
intact blood cells in urine. can see intact reds in sediment/ spun sample
Ddx - haematuria
- trauma
- cystitis
- renal bleeding
- from GIT
Define haemoglobinuria
contents of RBC in urine
Ddx - haemoglobinuria
in haemolytic anaemias, where reds have broken down in stored urine
Define myoglobinuria
mm oxygen carrying protein
Ddx - myoglobinuria
severe mm damage
Do you get RBC lysis in urine?
Yes - be careful with very dilute, alkaline urine let over time?????
Outline examination of urine sediment
- quantify: cells, crystals, casts, bacteria
- bacterial morphology
- quantify casts/field at 10x
- quantify cells/ field at 40x (if >100/field then TNTC)
What do WBCs in urine sediment indicate?
inflammation or infection (usually
What doe RBCs in urine sediment indicate?
haemorrhage or contamination from cystocentesis (usually
Describe ammonium biurate crystals
- neutral to alkaline pH
- dogs and cats with PSS
Describe bilirubin crystal
- most common in canine urine
- low #s is not clinically significant in dogs
- often significant in cats, horses
Describe calcium oxalate crystal
- any pH
- 2 forms: monohydrate - ethylene glycol toxicity OR dihydrate which can be found in normal urine
- horses can have low #s of these in urine
Describe struvite crystals
- commonest crystal in dog and cat urine
- may be seen in normal urine
- neutral to alkaline pH
Describe calcium carbonate crystals
- found in normal horse urine
What are casts? significance?
- all casts are derived from renal tubular epithelium
- appearance depends on transit time down tubule
- high #s indicate tubular damage
