Equine Renal and UT Dz Flashcards
Correct storage procedure of reagent strips
Kept refrigerated until use
What temperature should urine be with reagent strips?
Room temp before testing
Limitations when testing equine urine with a reagent strip
Strips expire
Use clean gloves
Equine specific strips aren’t available
What does an increase in nitrate indicate
Bacteriuria because G- bacteria synthesize nitrate reductase leading to nitrite production
How do you quantify protein concentration in urine and correct for changes in dilution? How does proteinuria affect SG?
Centrifuged to minimize effects of mucoproteins and protein aggregates
UPC corrects the effects of urine conc
Proteinuria ↑ SG
Pre-renal proteinuria
Abnormal amounts of Hb, Mb, bence-Jones proteins
May cause glomerulonephropathy
Renal proteinuria
↑ amounts of low molecular weight protein in urine from interstitial renal dz infection or inflamm. (from glomerular dz)
Post renal proteinuria
Inflamm. of the urinary tract or genitalia
How would you differentiate between hematuria, hemaglobinuria and methemoglobinuria?
Cytology
Evaluating hemolytic anemia with intravasc hemolysis with muscle injury and urine sediment
Hematuria
Bleeding at any level of the UT
Hemoglobinuira
Intravascular hemolysis (leading to pigment nephropathy) or in vitro hemolysis
Myoglobinuria
Rhabdomyolysis (painful muscle contractures with exercise and skeletal muscle fiber necrosis) → pigment nephropathy
Methemoglobinuria
Red maple leaf toxicity
High urine nitrate conc (false +)
Measuring SG
Refractometer
Criteria to determine AKI severity in dehydrated animals
Hyposthenuria
<1.008
Secondary to ↑ water intake, diuresis, primary or secondary DI
Due to milk diet in foals (normal)
Isosthenuria
1.008-1.014, cannot concentrate/ dilute urine→ renal failure
Hyperstenuria
> 1.014, mild nephron loss
What causes glucosuria?
Prerenal: PPID, alpha-2 agonist, parenteral nutrition, prolonged stress, neoplasia
Renal: proximal tubular dz
Prerenal azotemia
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
Renal azotemia
Decreased # or function of nephrons then glomeruli can’t filter out nitrogenous waste due to decreased GFR by renal injury
Post-renal azotemia
Caused by failure to excrete urine from the body due to obstruction or rupture of the bladder
How is SDMA useful in horses?
↑ in horses with symptomatic AKI
Electrolyte abnormalities of renal failure
ARF: hypochloremia, -calcemia, -natremia, hyperphosphatemia, hypo or hyperkalemia
CRF:2/3 hypercalcemia, 2/3 hyponatremia
Findings in a foal with a rupture bladder
↑ creat
How old are foals when they show signs of ruptured bladder?
How are urinary enzymes used?
Periods of inflamm and necrosis of tubules they ↑ = renal tubular damage (AKI)
VAKI (Veterinary acute kidney injury) scoring system
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
What happens to the accuracy of the urine cytologic eval if the urine sample left out?
Crystal lysis and cast dissolution if left out <1 hr
Crystals found in normal equine urine
Calcium carbonate crystals and calcium oxalate
Sometimes ca phosphate, struvte or hydroxyapatite
How many leukocytes and erythrocytes are found PHF in normal equine urine?
Less than 8 per hpf
How are fractional electrolyte excretion ratios used?
Describe the amount of specific electrolyte in urine compared to plasma
↑ fractional excretion = impaired renal tubular function
