Renal Function (dilini)

Question 1

What does the kidney excrete?

Answer 1

Urea, creatinine, K+, H+, NH4+, PO4+

Ca2+ (equine, rabbit)

Question 2

What does the kidney conserve?

Answer 2

Na+, Cl-, HCO3-, Ca2+, Mg2+, Glucose, Amino acids, Water

Question 3

How would you define GFR and what factors influence it?

Answer 3

The rate fluid moves from plasma to glomerular filtrate.
Influenced by: hydrostatic pressure in Bowman’s space, plasma oncotic pressure, renal plasma flow (blood vol, cardiac output).

Question 4

In what breed of dog is GFR naturally higher?

Answer 4

Greyhounds

Question 5

What is the normal GFR for dogs and cats?

Answer 5

Canine: 3-5ml/min/kg
Feline: 2.5-3.5ml/min/kg

Question 6

How do you measure GFR and what can you detect?

Answer 6

Measure clearance of a substance that is neither reabsorbed nor secreted (inulin, creatinine).
Can detect a 20% decrease in renal function.

Question 7

How can you evaluate tubular integrity?

Answer 7

Urine specific gravity, tubular proteinuria, water deprivation test, exogenous ADH, fractional excretion, biomarkers

Question 8

How can you evaluate glomerular integrity?

Answer 8

Creatinine, urea, GFR assessment, glomerular proteinuria

Question 9

What percentage of nephrons must be non-functional before a decrease in creatinine is seen?

Answer 9

75%

Question 10

Is creatinine or urea more efficient for diagnosing chronic renal failure?

Answer 10

Creatinine

Question 11

Biosynthesis of creatinine involved which two organ systems?

Answer 11

Renal and hepatic.

Question 12

How is urea excreted?

Answer 12

Primarily renal excretion in most animals.

Ruminants also salivary and rumen excretion.

Question 13

What is azotemia?

Answer 13

Increased serum urea and/or creatinine concentration.

Question 14

What other parameter must always be assessed with azotemia and for what reason?

Answer 14

Urine specific gravity - to determine if azotemia is pre renal or renal.

Question 15

Concentrated urine with azotemia indicates that it is….?

Answer 15

Pre-renal azotemia

Question 16

Pre renal azotemia can be caused by what?

Answer 16

Processes prior to the kidneys - dehydration, hypovolemia, decreased cardiac output / cardiac insufficiency, high protein diets, haemorrhage into GIT

Question 17

Poorly concentrated urine indicates what kind of azotemia?

Answer 17

Renal azotemia

Question 18

What can cause renal azotemia?

Answer 18

Congenital abnormalities, renal ischemia/necrosis, neoplasia, inflammation, infection, toxins

Question 19

What causes post renal azotemia and what USG will accompany it?

Answer 19

Failure to excrete urine. Any USG may accompany.

Question 20

What is N-acetyl-B-glucosaminidase (NAG) and what is it useful for?

Answer 20

A proximal tubule lysosomal enzyme useful for detecting tubular injury - amount may be directly correlated with severity.

Question 21

Outline the general parameters of diminished renal reserve

Answer 21

Approx 50% GFR, no azotemia, unable to tolerate additional insult

Question 22

Outline the general parameters of Chronic Renal Insufficiency

Answer 22

20-50% GFR, azotemia, polyuria, anemia

Question 23

Outline the general parameters of Chronic Renal Failure

Answer 23

20-25% GFR, azotemia, cannot regulate ECF (oedema), hypocalcaemia, metabolic acidosis, overt uraemia

Question 24

Outline the parameters of End Stage Renal Disease

Answer 24

> 5% GFR, terminal stages of uraemia

Question 25

What are the main causes of Chronic Renal Failure in dogs?

Answer 25

chronic tubulointerstitial nephritis, chronic polynephritis, chronic glomerulonephritis, amyloidosis, familial renal diseases, hypercalcaemic nephropathy, chronic obstruction

Question 26

What are the main causes of Chronic Renal Failure in cats?

Answer 26

chronic tubulointerstitial nephritis, chronic pyelonephritis, chronic glomerulonephritis, amyloidosis, polycystic kiney disease, neoplasia, granulomatous interstitial nephritis

Question 27

What are the main causes of Chronic Renal Failure in cattle?

Answer 27

chronic pyelonephritis, chronic interstitial nephritis, amyloidosis, renal infarction due to sepsis, renal vein thrombosis, leptospirosis, renal lymphoma

Question 28

What are the main causes of Chronic Renal Failure in horses?

Answer 28

chronic glomerulonephritis, chronic interstitial nephritis, chronic pyelonephritis, amyloidosis

Question 29

What are the main clinical findings in an animal with chronic renal failure?

Answer 29

PU/PD, vomiting, anorexia, weight loss, lethargy

Question 30

How can you differentiate chronic from acute renal failure?

Answer 30

renal size, history of previous PU/PD, non-regenerative anaemia, weight loss & poor haircoat, parathyroid gland size, hypothermia, hyperkalemia

Question 31

What causes anaemia in chronic renal failure?

Answer 31

Inadequate erythropoetin (EPO) production, decreased RBC lifespan (damaged by substances no longer being cleared), decreased marrow response to EPO, decreased platelet function

Question 32

What occurs in Fanconi Syndrome and what is the first abnormality usually noted?

Answer 32

Impaired proximal renal tubular resorbtion. Glucosuria.

Question 33

In which breeds is Fanconi Syndrome hereditary?

Answer 33

Basenji, Schnauzer, Norweigen Elkhound, Sheltie

Question 34

What can cause induced Fanconi Syndrome?

Answer 34

Toxins (lead) or drugs (gentamycin, amoxil)

Question 35

What is the definition of urine specific gravity and what is it used to measure?

Answer 35

Ratio of weight of urine to weight of an equivalent volume of pure water. Measures renal tubular function.

Question 36

What are the causes of dilute urine?

Answer 36

renal failure, hypo/hyperadrenocorticism, hypercalcaemia, diabetes mellitus, hyperthyroidism, diuretic therapy, diabetes insipidus

Question 37

What can urine pH be used to assess?

Answer 37

Acid-base status and the ability of the kidneys to regulate acid-base balance

Question 38

What is the normal range for urine pH?

Answer 38

5.5-7.5

Question 39

How can dietary factors affect urine pH?

Answer 39

Herbivores usually have alkaline urine. | Carnivores usually have acidic urine.

Question 40

Is trace protein in urine significant?

Answer 40

Trace protein in concentrated urine is less significant than in dilute urine.

Question 41

What might give false positive Proteinuria results?

Answer 41

Alkaline urine, urea-producing bacteria, disinfectant residue

Question 42

What might give false negative proteinuria results?

Answer 42

Acidic/dilute urine, bence jones proteins

Question 43

What is proteinuria observed with?

Answer 43

Inflammation, haemoglobinuria, hematuria, myoglobinuria, pyuria, glomerular/tubular disease

Question 44

When might glucosuria be detected in an otherwise healthy cat?

Answer 44

When it is stressed

Question 45

What might cause a false positive result for glucosuria?

Answer 45

Contamination (H2O2, bleach), obstructed cats

Question 46

What might cause a false negative for glucosuria?

Answer 46

Ascorbic acid, tetracyclines, high concentrations of ketones, refrigerated urine

Question 47

What can cause blood glucose to exceed the urine threshold?

Answer 47

diabetes mellitus, shock, glucose fluids, anaesthesia, excessive glucocorticoids, stress

Question 48

What may be the cause when there is glucosuria with normal blood glucose levels?

Answer 48

renal tubular disease, primary renal glycosuria, pups and kittens

Question 49

Ketosis can be caused by?

Answer 49

Diabetes, insulinoma, high fat/low carb diets, prolonged fasting, pregnancy toaxaemia, primary ketosis in ruminants

Question 50

Is bilirubinuria ever normal?

Answer 50

Normal in dogs with a high specific gravity. | Never normal in cats at any specific gravity.

Question 51

What might cause false negative bilirubinuria results?

Answer 51

aged urine samples, exposure to UV light, ascorbic acid

Question 52

The urine blood strip test will react positively to what?

Answer 52

Red blood cells, free hemoglobin, free myoglobin

Question 53

What may cause a false positive urine blood strip test?

Answer 53

contamination (bleach, iodide, bromide), dog in heat, cystocentesis

Question 54

What might cause a false negative urine blood strip test?

Answer 54

Urine is not well mixed - RBCs sediment out quickly

Question 55

Hematuria indicates haemorrhage caused by?

Answer 55

inflammation, calculi, bleeding disorders, parasites, estrus, prostatic diseases, trauma, neoplasia

Question 56

Red and cloudy urine sample, after centrifugation becomes clear with sediment that reveals red cells

Answer 56

Hematuria

Question 57

Reddish-brown urine sample which does not clear after centrifugation. Patient clinically anaemic.

Answer 57

Hemoglobinuria

Question 58

Sample appears red but clears quickly with centrifugation. Sediment does not reveal any red blood cells.

Answer 58

Myoglobinuria

Question 59

What is the function of the kidneys?

Answer 59

To maintain extracellular fluid, eliminate wastes of normal metabolism and excrete xenobiotics & their metabolites.