w/c 3-Mar-14 Flashcards
Which part of nephron is impermeable to water?
Thick ascending limb is impermeable to water.
Actively transports Na/K/Cl out
What stimulates Renin to be secreted from afferent arteriole?
-In response to reduced stress or in response to sympathetic nerves
Which arteriole does Angiotensin II constrict?
Efferent arteriole.
Enhances water/Na+ reabsorbtion
Stimulates aldosterone secretion
Where does Aldosterone act?
Distal tubule
What is the shock dose of fluids in dogs? cats?
Same as blood volume:
a) Cat: 40-69mL/kg
b) Dog: 60-90mL/kg
What is Oliguria?
Less than normal urine output
Differentiate between Retrograde and Antegrade contrast
Retrograde: Contrast injected Caudal to Cranial
Antegrade: Contrast injected Cranial to Caudal
What size/gauge catheter would you choose to deliver shock rate fluids
Short, large bore catheter
Why does urea increase in dehydration
Passively diffuses with water from tubular lumen. Amount absorbed varies inversely with rate of urine flow. Decrease urine flow= increased absorption.
OR
Dehydration = vasocontriction of peripheral function = decrease blood flow to kidney–> decrease GFR
Why is Creatinine a more reliable indicator of renal function?
Not affected by diet or catabolic factors. Very insensitive in birds. Differences in levels last longer than [urea]
What factors might falsely increase urine specific gravity
May be falsely increased by glucose or protein in the urine
What is the significance of Isothenuria
Fixed USG of 1.008-1.012 i.e. same as glomerular filtrate. Kidney not concentrating or diluting urine
Normal USG for dog, cat, horse
- 025 horse/ruminant
- 030 dog
- 035 cat
How will calcium levels vary in kidney failure. Any species differences?
Most dogs/cats with renal failure = hypo/normocalcemic (due to hyperphoshatemia binding calcium)
Horses will be hypercalcemic (kidney major excretory route)
What will happen to Phosphorus levels in renal disease?
Hyperphosphatemia is associated with decreased GFR so levels will be increased in dogs and cats
How is Amylase/Lipase associated with renal disease
Amylase/Lipase are pancreatic enzymes but are cleared by the kidneys so moderate increases are seen in dogs with renal dsease
What type of anaemia might you expect from renal disease?
Mild non regenerative anaemia.
Secondary to lack of erythropoetin production
Considerating when assessing urine pH from free catch sample
Need fresh sample as urine becomes alkaline on standing.
Cystitis leads to higher pH due to conversion of urea by bacteria
Bilrubinurea is always significant in what species
Bilrubinurea is always significant in cats.
Small amounts normal in dogs
Which type of crystals are normally present in horse urine
Calcium carbonate/ Calcium Oxalate
Mechanism by which Uraemia leads to Secondary renal hyperparathyroidism
Decreased GFR leads to hyperphosphataemia which precipitates ionised calcium. Decreased activation of vitamin D, decreased absorption of calcium, stimulates PTH secretion and calcium release via osteoclastic bone reabsorption
aka increased PTH release
Effects of secondary renal hyperparathyroidism on the kidney
Renal disease is perpetuated by nephrocalcinosis = calcification of tubular BM. Gritty when cut
Immune-mediated glomerulonephritis is associated with
Specific viral infections - FeLV
Chronic bacterial infection –> pyometra
Chronic parasitism
Neoplasia
Diagnosis of immune mediated glomerulonephritis
IF/IHC to indicate the presence of immunoglobulin or complement.
Grossly glomeruli visible as pinpoint red/pale
Increased celluratity
Breed predisposition to glomerular amyloidosis
Shar pei dogs.
Disease often associated with chroninc inflammatory disorders or neoplasia. Commonly idiopathic.
Consequences: Nephrotic syndrome/ proteinaemia
Diagnosis of Glomerular Amyloidosis
Brown staining of glomeruli following treatment of iodine.
Bacterial.embolic nephritis is also known as
Acute suppurative glomerulitis.
Bacteraemia–> bacteria lodge in glomerular/intersitial capillaries –> microabsecess
Actinobacillus equlli in foals
Erysipelothrix rhusiopathiae in pigs
Corynebacterium pseudotuberculosis in sheep/goats
