Clinical pathology: clinical chemistry-(i)Evaluation of renal function Flashcards
Are ketones usually present in the urine of dogs and cats?
No, not normally present
What can lead to ketone production?
Inadequate consumption of carbohydrate or impaired utilisation of carbohydrates
Give 5 causes of ketonuria.
(i)diabetic keto-acidosis
(ii)starvation or prolonged fasting
-glycogen storage disease
-low carbohydrate-high fat diet
-persistent hypoglycaemia(decreased insulin induces ketone formation)
Check flashcard folder numbers 1 and 2 for further information
Bilirubin: if present in the urine, in which form is it usually found?
-Conjugated form
- In which type of urine is it normal to have a small amount of bilirubin?
- Is this a common finding in cats?
- Concentrated urine of normal male dogs
- This is not normally found in cat urine.
How is bilirubin made in the body?
-Bilirubin is derived from the breakdown of heme by the reticuloendothelial system.
Give 5 causes of bilirubinuria.
- Haemolysis
- Liver disease
- Extrahepatic biliary obstruction
- Fever
- Starvation
What is the term used to describe an increase in the level of bilirubin in the blood.
Hyperbilirubinaemia
What is the disadvantage of using dipstick when testing for the presence of blood in urine?
Dipstick tests do not differentiate from intact RBCs or haemoglobin.
Give 8 different causes of haemoglobinuria from haemolysis.
-Transfusion reaction
-Immune mediated haemolytic anaemia
-Disseminated intravascular coagulation(DIC)
-Splenic torsion
-Severe hypophosphatemia
-Heat stroke
Zinc toxicity
-Phosphofructokinase or pyruvate kinase deficiency
Describe how to prepare a urinary sediment.
1/Sediment preparation
a. Perform on fresh urine samples.
b. Centrifuge 5 to 10 ml of urine at 1000 to 1500 rpm for 5 minutes. stain with Sedi-Stain.
c. Number of casts is recorded per low-power field, and cells are recorded per high-power field.
What is the term used to describe excessive number of RBCs in urine?
Haematuria
Give 12 different causes of haematuria.
-trauma
-urolithiasis
-neoplasia
-UTIs idiopathic feline lower urinary tract disease
chemically induced cystities
-systemic diseases associated with haemorrhage
-renal infarct
-nephritis
-nephrosis
-parasites
-nephrosis
-genital tract contamination
What is the term used to describe excessive WBC’s in urine sediment? What does this indicate?
Pyuria
It indicates inflammation somewhere in the urinary tract or contamination from the genital tract.
What would cause clumped WBC’s?
Clumped WBC’s are usuallly due to infectious organisms.
What are the 3 different types of epithelial cells that can be found in the urine?
(i) Squamous epithelial cells
(ii) Transitional epithelial cells
(iii) Renal epithelial cells
Is the presence of each of the different types of epithelial cells in urine normal?
For transitional epithelial cells and renal epithelial cells, when can their values be increased?
-Squamous epithelial cells(large, polygonal cells with small, round nuclei)
This is a common finding in voided or catheterised samples.
-Transitional epithelial cells
A small number is normal. Usually increased in infection, irritation or neoplasia
-Clumps or “rafts” are most common in neoplasia
-Renal epithelial cells
(i)Small epithelial cells from the renal tubules or pelvis
(ii)Appearance in urine is never normal and is observed in patients with ischaemic, nephrotoxic or degenerative renal disease.
What are casts?
Casts are cylindrical molds formed in the renal tubules composed of aggregated protein or cells.
Give 5 examples of casts in urine.
- Hyaline
- Cellular casts
- Granular casts
- Waxy casts
- Broad casts
How is hyaline formed as a cast and what may trigger its formation?
It is a pure protein precipitates of Tamm-Horsfall mucoprotein.
It dissolves rapidly in dilute or alkaline urine.
It has the least pathologic significance and may form transiently with fever, exercise or passive congestion to the kidney.
What are the 6 different types of cellular casts and describe how they are formed?
(i) White cell casts-suggest pyelonephritis nbut may also be caused by interstitial neohritism nephrosis or glomerulonephritis.
(ii) Red cell casts are fragile and rarely found. They may be noted in acute glomerulonephritis.
(iii) Hameoglobin casts are casts where the haemoglobin colour is retained in the cast.
(iv) Renal epithelial casts -severe tubular injury and suggest acute tubular necrosis or pyelonephritis.
(v) Renal fragments are a variant of epithelial casts where portions of the renal tubules slough into urine, their appearance suggests severe renal injury.
(vi) Mixed casts contain multiple cell types.
NOTE: Pyelonephritis is inflammation of the kidneys.
What do granular casts represent? How can fatty casts be formed?
granular casts represent the degeneration of cells or precipitation of filtered plasma proteins.
fatty casts are a type of granular cast that may be seen in nephrotic syndrome or diabetes mellitus.
What do waxy casts represent?
Waxy casts represent the final stage of degeneration of granular casts. they suggest chronic intrarenal stasis and are found in advanced chronic renal disease.
What are broad casts and how are they formed?
Broad casts are wide casts that form in collecting ducts or dilated distal nephron. they suggest severe intrarenal stasis and tubular obstruction.
Give 4 examples where there can be bacteriuria without pyuria.
(i) hyperadrenocorticism
(ii) diabetes mellitus
(iii) immunosuppression
(iv) cats with chronic renal disease
NOTE: The absence of bacteria does not rule out UTI.
Yeasts and fungal hyphae in sediment are usually contaminant.
How are crystals formed in urine?
They are usually an artifact of storage urine and refrigeration.
Where are struvite crystals usually found?
Struvite crystals are found in alkaline urine and may be found in normal animals or in those with struvite urinary stones.
In what type of urine is each of the following crystals found and where relevant, state the condition to which they are usually associated.
(i) calcium phsophate crystals
(ii) calcium carbonate crystals
(iii) amorphous phosphate crystals
(iv) ammonium biurate crystals
(v) uric acid crystals
(vii) urate crystals
(viii) calcium oxalate crystals
(ix) Cystine crystals
(x) billirubin crystals
(xi) oxalate monohydrate
(i) i)calcium phsophate crystals-alkaline urine
(ii) calcium carbonate crystals-alkaline urine
(iii) calcium carbonate crystals-alklaine urine
(iii) amorphous phosphate crystals-alkaline urine
(iv) ammonium biurate crystals-alkaline urine
(v) uric acid crystals-acidic urine and they are associated with the Dalmatian breed
(vii) urate crystals assoaciated with liver disease and portosystemic shunt
(viii) calcium oxalate crystals-acidic urine
(ix) Cystine crystals-acidic urine and associated with cystinuria
(x) billirubin crystals found normally in concentrated dog urine
(xi) oxalate monohydrate crystals are found in acute renal failure owing to ethylene glycol ingestion.
Is it normal to find sperm in the urine of intact males?
Yes
In what condition could there be the presence of amorphous debris in the urine?
Amorphous debris associated with acute intrinsic renal failure
When can mucous threads or fibrin strands be seen?
Mucous threads or fibrin strands seen in lower urinary tract or genital inflammation
Are parasite ova from Doctophyma renale or Capillaria plica in the urine a common finding?
No, parasite ova from Doctophyma renale or Capillaria plica are rarely seen in the urine.
What are lipid droplets associated with?
Lipid droplets are associated with cellular degeneration.
NOTE: Foreign material may be present, especially in voided samples.
Precipitates of urine stain may look like urinary crystals.
