Urine Casts Flashcards
What do casts give us a snapshot of?
The lumen of the renal tubules and can indicate damage
What is the matrix of the cast called?
Tamm-Horsfall Mucoprotein
What do casts look like?
Cylindrical
Same size as the lumen
ends are tapered, irregular, or round
May have inclusions
Where are casts formed?
The distal convoluted tubule
Collecting ducts
How are casts formed?
Secreted protein precipitates in acidic conditions and forms casts shaped like the tubules
What does the type of cast depend on?
How quickly the filtrate moves through the tubules
Slower filtrate=
Waxy casts
Bad
Sort of slowly filtrate=
Hyaline casts
What pH of urine do casts dissolve quickly in?
Alkaline urine
What species do we see casts less often?
Herbivores
What does seeing casts in 0-1/hpf often indicate?
Lesions
Does the number of casts present indicate the severity of the disease?
No
Which casts are clear, colorless, transparent, and do not have inclusions?
Hyaline casts
What kind of cast indicates a mild form of renal irritation
Hyaline casts
What kind of cast increases with fever, poor renal profusion, strenuous exercise, general anesthesia?
Hyaline casts
How does general anesthesia cause Hylaine casts?
When the blood pressure drops there is a temporary period of poor renal profusion
What kind of light is the best to look at Hyaline casts under a microscope?
Dim light
What are Hyaline casts with remnants of cells?
Granular casts
What are granular casts made up of?
Degenerated renal cells, RBCS, WBCs
With what condition do you see increased granular casts
Acute nephritis
What does the presence of granular casts indicate?
More severe renal damage than hyaline casts
What are hyaline casts with renal epithelial cells incorporated?
Epithelial Casts
What condition can you see epithelial casts?
Acute nephritis
Are epithelial casts common?
No, they are rare
What kind of casts are wider hyaline casts with a “dull” appearance
Waxy casts
What are the characteristics of waxy casts?
Square ends
Bigger
Colorless to gray
Refractile
What is considered the worst casts?
Waxy casts
What do waxy casts indicate?
Chronic severe degeneration of the tubules
Slowly moving filtrate
Which casts contain retractile bodies and are sometimes referred to as oval fat bodies
Fatty Casts
Where are Fatty casts seen?
In cats with renal disease
rarely in dogs with diabetes mellitus
What kind of casts have WBCs in the matrix?
Leukocyte casts
What does the presence of leukocyte casts indicate?
Inflammation of the renal tubules
What kind of casts have RBCs in the matrix?
Erythrocyte casts
What causes the presence of Erythrocyte casts?
Renal bleeding due to trauma, bleeding disorders
What are erythrocyte casts part of?
The inflammatory response
What pH do casts form in?
Acidic urine
How do you report casts to the veterinarian?
1+, 2+, 3+,4+ and type
