Equine Renal and UT Dz

Question 1

Correct storage procedure of reagent strips

Answer 1

Kept refrigerated until use

Question 2

What temperature should urine be with reagent strips?

Answer 2

Room temp before testing

Question 3

Limitations when testing equine urine with a reagent strip

Answer 3

Strips expire
Use clean gloves
Equine specific strips aren’t available

Question 4

What does an increase in nitrate indicate

Answer 4

Bacteriuria because G- bacteria synthesize nitrate reductase leading to nitrite production

Question 5

How do you quantify protein concentration in urine and correct for changes in dilution? How does proteinuria affect SG?

Answer 5

Centrifuged to minimize effects of mucoproteins and protein aggregates
UPC corrects the effects of urine conc
Proteinuria ↑ SG

Question 6

Pre-renal proteinuria

Answer 6

Abnormal amounts of Hb, Mb, bence-Jones proteins
May cause glomerulonephropathy

Question 7

Renal proteinuria

Answer 7

↑ amounts of low molecular weight protein in urine from interstitial renal dz infection or inflamm. (from glomerular dz)

Question 8

Post renal proteinuria

Answer 8

Inflamm. of the urinary tract or genitalia

Question 9

How would you differentiate between hematuria, hemaglobinuria and methemoglobinuria?

Answer 9

Cytology
Evaluating hemolytic anemia with intravasc hemolysis with muscle injury and urine sediment

Question 10

Hematuria

Answer 10

Bleeding at any level of the UT

Question 11

Hemoglobinuira

Answer 11

Intravascular hemolysis (leading to pigment nephropathy) or in vitro hemolysis

Question 12

Myoglobinuria

Answer 12

Rhabdomyolysis (painful muscle contractures with exercise and skeletal muscle fiber necrosis) → pigment nephropathy

Question 13

Methemoglobinuria

Answer 13

Red maple leaf toxicity
High urine nitrate conc (false +)

Question 14

Measuring SG

Answer 14

Refractometer
Criteria to determine AKI severity in dehydrated animals

Question 15

Hyposthenuria

Answer 15

<1.008
Secondary to ↑ water intake, diuresis, primary or secondary DI
Due to milk diet in foals (normal)

Question 16

Isosthenuria

Answer 16

1.008-1.014, cannot concentrate/ dilute urine→ renal failure

Question 17

Hyperstenuria

Answer 17

> 1.014, mild nephron loss

Question 18

What causes glucosuria?

Answer 18

Prerenal: PPID, alpha-2 agonist, parenteral nutrition, prolonged stress, neoplasia
Renal: proximal tubular dz

Question 19

Prerenal azotemia

Answer 19

Horses with AKI + normal renal function
Decrease in renal blood flow, reduced GFR, increased creat
Caused by dehydration, hypovolemic shock or cardiac failure
<1.018 USG, <20 mEq/L urine Na, UPC ratio >20:1, decrease potassium

Question 20

Renal azotemia

Answer 20

Decreased # or function of nephrons then glomeruli can’t filter out nitrogenous waste due to decreased GFR by renal injury

Question 21

Post-renal azotemia

Answer 21

Caused by failure to excrete urine from the body due to obstruction or rupture of the bladder

Question 22

How is SDMA useful in horses?

Answer 22

↑ in horses with symptomatic AKI

Question 23

Electrolyte abnormalities of renal failure

Answer 23

ARF: hypochloremia, -calcemia, -natremia, hyperphosphatemia, hypo or hyperkalemia
CRF:2/3 hypercalcemia, 2/3 hyponatremia

Question 24

Findings in a foal with a rupture bladder

Answer 24

↑ creat

Question 25

How old are foals when they show signs of ruptured bladder?

Question 26

How are urinary enzymes used?

Answer 26

Periods of inflamm and necrosis of tubules they ↑ = renal tubular damage (AKI)

Question 27

VAKI (Veterinary acute kidney injury) scoring system

Answer 27

0: ↑ sCr <150% from baseline
1: ↑ sCr <150%-199% or absolute ↑ >0.3 mg/dL from baseline
2: ↑sCr <200%-299%
3: ↑ sCr >300% or absolute ↑ >4.0 mg/dL from baseline

Question 28

What happens to the accuracy of the urine cytologic eval if the urine sample left out?

Answer 28

Crystal lysis and cast dissolution if left out <1 hr

Question 29

Crystals found in normal equine urine

Answer 29

Calcium carbonate crystals and calcium oxalate
Sometimes ca phosphate, struvte or hydroxyapatite

Question 30

How many leukocytes and erythrocytes are found PHF in normal equine urine?

Answer 30

Less than 8 per hpf

Question 31

How are fractional electrolyte excretion ratios used?

Answer 31

Describe the amount of specific electrolyte in urine compared to plasma
↑ fractional excretion = impaired renal tubular function