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Clinical Pathology > Urinary System > Flashcards

Urinary System Flashcards

1
Q

Processes that regulate urine formation

A
  • glomerular filtration (passive)
  • tubular absorption (active or passive)
  • tubular secretion (active or passive)
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2
Q

Glomeruli

A
  • capillary endothelium
  • basement membrane
  • glomerular epithelial cells (podocytes) with foot processes
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3
Q

Evaluation of glomerular filtration

A
  • excretion of substances that pass freely thru the glomeruli –> size <2.4 - >3.4, positive charged passes more freely
  • albumin is 3.5 nm and negatively charged –> not present in urine of cats, cattle, horses, in low conc in dogs
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4
Q

Glomerular filtration rate

A

Fluid that goes from plasma to glomerular filtrate

  • assessed by rate some substances are cleared from the plasma
  • GFR depends on renal plasma flow
  • RPF depends on blood volume, cardiac output, # of functional glomeruli, constriction/dilation of afferent/efferent arterioles
  • other: intracapsular hydrostatic pressure, oncotic pressure
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5
Q

The ideal biomarker for GFR

A
  • not bound to protein
  • pass freely through filtration barrier
  • neither excreted nor absorbed by renal tubules
  • insulin, iohexol, manitol nearly meet the criteria
  • creatinine is secreted very little and meets criteria
  • imagining can be used
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6
Q

Function of renal tubules is assessed comparing ___________

A

The urinary excretion of a plasma substance to insulin
- if greater than insulin –> there is tubular secretion, and if lower there is resorption or does not pass freely though filtration barrier

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7
Q

Na

A

75% resorbed in proximal tubules

  • passively resorbed in loop of Henle
  • ADH stimulates absorption in the loop of Henle
  • aldosterone stimulates absorption in the collecting ducts
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8
Q

Cl

A

75% resorbed in the proximal tubules

  • passivley resorbed in the loop of Henle
  • resorbed passively in distal nephron due to a gradient formed by Na
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9
Q

HCO3

A

90% conserved in the proximal tubules via H secretion

  • collecting ducts type A intercalated cells increase resorption
  • collecting ducts Type B intercalated cells decrease resorption when there is excess
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10
Q

K

A

Most is resorbed prior to distal tubules

  • secreted by principal cells in collected ducts (promoted by aldosterone)
  • movement into tubules enhanced by high flow and inhibited by low flow
  • ADH promotes secretion in cortical collecting ducts
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11
Q

H

A

Secreted by type A intercalated cells in distal nephron

  • aldosterone and acidemia promote secretion
  • limited amount secreted in proximal tubule
  • most renal secretion of H is within NH4 and either HPO4 or H2PO4
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12
Q

Ca

A

80-85% resorbed in proximal tubules and loop of Henle

  • PTH promotes resorption
  • vit D promotes resorption
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13
Q

PO4

A

85-90% resorbed in proximal tubule

  • enhanced by hypophosphatemia and insulin
  • inhibited by hyperphosphatemia and PTH
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14
Q

Mg2

A

Near all resorbed in the loop of Henle

- ADH, PTH, glucagon, calcitonin and B-agonists stimulate resorption

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15
Q

Glucose

A

All resorbed in proximal tubules

- mechanism involve transporter proteins that can be overwhelmed by high saturation of plasma glucose (glucosuria)

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16
Q

Proteins and amino acids

A

Nearly all resorbed in proximal tubules

  • AA use 7 different transporters for 7 AA groups
  • larger proteins (inclu albumin) enter the tubular cells by endocytosis and are degraded to amino acids
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17
Q

What are 3 important receptors mediating endocytosis?

A

Megalin, aminionless, and cubalin

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18
Q

Urea

A

60-65% resorbed in proximal tubules

  • ADH enhance resorption in distal nephron
  • responsible for 50% of hypertonicity of the medulla
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19
Q

Creatinine

A

Small amounts are secreted in proximal tubules (dogs)

- does not happen with horses and cats

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20
Q

Water

A

30% of renal perfusion flow becomes ultrafiltrate, 75% is passively resorbed in proximal tubules

  • passively resorbed in the loop of Henle as it enters hypertonic medulla
  • collecting ducts are permeable in presence of ADH thru aquaporin
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21
Q

_____ is imperbeable to water

A

Ascending loop of Henle

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22
Q

Concentrating ability

A

Ability to resorb water in excess to resorption of solutes

- will increase osmolarity

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23
Q

Diluting ability

A

Ability to resorb solutes in excess to resorption of water

- will decrease osmolarity

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24
Q

Isosthenuria

A

Urine osmolality is the same of plasma osmolality

- USG 1.007-1.013

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25
Q

Hyposthenuria

A

Urine osmolality is less than isosthenuric values

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26
Q

Eusthenuria

A

Osmolality that is expected for an animal with adequate renal function
- around hyposthenuria

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27
Q

Hypersthenuria

A

Very concentated urine

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28
Q

Urine concentration

A

ADH must be present!

  • stimuli: hyperosmolality, decreased cardiovascular pressure, increased angiotensin (less extent)
  • epithelial cells of distal nephron must be responsive to ADH
  • concentration gradient: medulla osmolality must be greater than that of the fluid in the tubules
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29
Q

Urine dilution

A

Na and Cl must actively transported from the tubular fluid to the interstitial fluid by epithelial cells in the ascending loop of Henle
- very little water removed by the distal nephron

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30
Q

With chronic renal insufficiency, renal tissue is _______

A

Inadequate to maintain health

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31
Q

At ____ of normal GFR, animal is clinically healthy but animal has less tolerance to insults

A

50%

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32
Q

Chronic renal failure has a GFR of ______

A

20-50% of normal

  • azotemia and anemia appears
  • polyuria due to decreased concentrating ability
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33
Q

CRF - symptoms

A
  • hypocalcemia (not in horses)
  • metabolic acidosis –> kidneys can’t regulate fluid volume or electrolyte balance
  • uremia
  • neurologic, GI, cardio complications
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34
Q

End-stage renal failure

A

GFR is <5% of normal

- terminal stages of uremia with oliguria or anuria

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35
Q

When more than ___ of the nephrons are lost, the animal loses the ability to concentrate urine

A

2/3

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36
Q

When more than ____ of the nephrons are lost, the animal becomes azotemic

A

3/4

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37
Q

Reasons for loss of concentrating ability

A
  • more solutes presented to remaining nephrons –> solute diuresis
  • medullary hypertonicity is not maintained –> medullary tissue is damage or blood flow is abnormal, decreased Na/Cl absorption in ascending loop of Henle, damaged cells in distal nephron less responsive to ADH
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38
Q

Polyruia in chronic renal insufficiency or failure

A

Not as severe as in diuretic states (ex: diabetes insipidus)

  • GFR is decreased –> decreased filtered volume
  • polyuria precedes azotemia (cats can concentrate more than other species, may be able to keep more concentrating ability along with azotemia)
  • progression of renal disease and nephron loss leads to oliguria or anuria
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39
Q

Evidence of insufficiency or failure

A
  • azotemia: increased BUN or creatinine on plasma due to decreased GFR
  • low USG due to loss of concentrating ability
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40
Q

Evidence of chronicity

A

Clinical findings including duration of signs

- lab findings: anemia, hypocalcemia (may also occur in acute renal failure, or hypercalcemia in horses)

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41
Q

Acute renal failure

A

Reversible, or irreversible, abrupt (hours or days), disease or insult that markedly decreases GFR
- usually toxicants, renal ischemia or infections

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42
Q

Azotemia

A

Magnitude of azotemia does not differentiate acute from chronic (is mild to severe in both cases)
- occurs more rapidly in acute (days), than in chronic renal failure (weeks to months)

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43
Q

Acute renal failure - urine volume and USG

A

Abrupt nature of acute failure –> no time for nephron hypertrophy –> very low GFR –> oliguria or anuria

  • urine may be concentrated if formed before insult
  • may be isosthenuric
  • not expected to be hyposthenuric!!
  • acid base and electrolyte status may become abruptly abnormal (hyperkalemia and acidemia)
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44
Q

Increased BUN and/or creatinine

A

Azotemia

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45
Q

Uremia

A

Urinary constituents in blood –> clinical signs reflecting renal failure
- vomiting, diarrhea, coma, convulsions, ammoniacal odor on breath

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46
Q

Pre-renal azotema pathogenesis

A

Any process that decreases RPF –> decreases GFR –> volume receptors sense reduced blood flow –> triggers angiotensin-renin system –> angiotensin 2 constricts afferent and efferent glomerular arterioles –> further decreases GFR
- hypovolemia –> increase Na absorption and water in proximal tubules –> increased BUN passive resorption –> decreased flow rate –> more time for resorption

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47
Q

Azotemia in face of protein losing nephropathy and hypoalbuminemia

A

Decreased oncotic pressure –> hypovolemia

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48
Q

Clinical hypoadrenocorticism

A

Aldosterone deficiency –> hyperkalemia –> decreased CO –> decreased arterial bp –> decreased GFR, increased loss of Na –> increase water loss –> hypovolemia

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49
Q

Severe intestinal hemorrhage causes

A

Pre-renal azotemia

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50
Q

Renal azotemia

A

Any renal disease that leads to major decreased GFR

  • loss of nephrons
  • decreased vascular potency within kidneys
  • decreased glomerular permeability
  • increased renal interstitial pressure
  • increased intratubular pressure
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51
Q

Renal azotemia - pathogenesis

A

Loss of 65-75% of the nephrons –> decrease GFR –> azotemia

- processes that contribute for pre-renal may also be present

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52
Q

With post-renal azotemia, the cause of increased BUN/creatinine is ______ to the nephron

A

Distal

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53
Q

Pathogenesis of obstructive azotemia

A

Release of vasoactive substances –> constrict glomerular arterioles –> decrease GFR
- impaired flow –> increased intracapsular pressure –> decreases GFR –> as less ultra filtrate is formed intracapsular pressure tends to decrease

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54
Q

Pathogenesis of azotemia caused by leakage of urine within the body

A

Leakage in peritoneal cavity –> BUN and creatinine enter plasma via passive diffusion thru mesothelium (BUN equilibrates faster than creatinine)

  • leakage in tissue surrounding urinary tract –> diffusion from extra to intravascular azotemia
  • if intestinal excretion of BUN/creatinine does not compensate decreased urinary excretion –> azotemia
  • processes that lead to pre-renal or renal azotemia may be present
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55
Q

Increased urea production

A

Increased proteolysis –> generates more NH4 –> increased urea synthesis by hepatocytes

  • if rate of urea prodcution exceeds rate of urea excretion –> azotemia
  • renal reserve –> increased excretion of increased BUN –> mild-no azotemia
  • intestinal hemorrhage = high protein diet + hypovolemia
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56
Q

Azotemia and uremia criterion involves _____

A

USG

  • renal and extrarenal factors that may affect concentrating ability must be considered
  • exclusively pre renal –> ADH simulus (>1.030 in dogs, >1.040 in cats, >1.025 in horses/cattle)
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57
Q

If USG below those values and no evidence of increased urea production _______

A

Then there is loss of concentration ability

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58
Q

USG in renal disease

A
  1. 007-1.013 due to tubulointerstitial impairment and loss of nephrons
    - USG may be >1.013 but still inappropriately low if: decrease GFR more than tubular function, high urine concentration of glucose (USG overestimated), plasma osmolality is increased
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59
Q

Extra-renal

A

Azotemia develops from hypovolemia

  • distal nephron not responsive to ADH (nephrogenic diabetes insipidus)
  • solute overload: too much solute entering the loop of Henle –> high flow rate –> decreased absorption of fluid
60
Q

Decreased medullary hypertonicity

A
  • prolonged hyponatremia or hypochloremia
  • blocked sodium and chloride
  • decreased urea production due to liver disease
  • solute overload or prolonged diuresis
61
Q

Urea nitrogen concentration in plasma

A

Many labs report urea directly, but frequently reported based on its nitrogen content
- sample: serum or plasma

62
Q

Increased urea nitrogen due to decreased excretion

A 
Pre-renal:
- hypovolemia, decreased CO, shock
Renal: 
- inflammatory
- amyloidosis
- toxic nephrosis
- renal ischemia/hypoxia
- congenital
- hydronephrosis
-neoplasia
Post-renal
- obstruction, leakage
63
Q

Increased urea nitrogen due to increased production

A
  • intestinal hemorrhage
  • dietary
  • increased catabolism
64
Q

Decreased urea nitrogen due to hepatic insufficiency

A

Extensive hepatocellular damage (>80%) –> impaired urea cycle –> decreased UN and increased NH4

65
Q

Decreased urea nitrogen due to portosystemic shunt

A
  • less NH4 delivered to hepatocytes

- less uptake of NH4 by hepatocytes (atrophy, necrosis or fibrosis)

66
Q

Decreased urea nitrogen due to increased urea excretion

A

Less water resorption (ex: osmotic diuresis) –> less concentration gradient –> less urea is reabsorbed
- central and nephrogenic diabetes insipidus lack of ADH activity –> less urea and water resorption

67
Q

Urea is responsible for ____ of medulla hypertonicity

A

50%
- decreased urea resorption –> decreased medulla hypertonicity –> decreased concentration gradient –> decreased concentration ability –> polyuria –> dehydration/hypovolemia –> azotemia

68
Q

Creatinine concentration on serum or plasma

A
  • sample: serum or plasma, up to 4 days at RT and 1-3 months -20C
  • test: dry chemistry and wet, colorimetric
69
Q

Increased creatinine concentration due to decreased GFR

A

Process may be pre, renal or post renal

70
Q

Increased creatinine due to increased production and release from myocytes

A
  • only if excretion is impaired (ex: rhabdomyolysis in horses)
71
Q

Increased creatinine is common in

A
  • greyhounds

- neonate foals if placenta clearance is not adequate (should disappear after birth)

72
Q

Decreased creatinine

A

Not clinically significant

  • decreased muscle mass
  • hypoproteinemia (slightly decreased)
73
Q

Creatinine clearance rate

A

Rate by which creatinine is cleared from blood

  • an indicator of GFR
  • causes of decrease: prerenal, renal, postrenal
74
Q

Indications for creatinine clearance rate

A
  • assess GFR in nonazotemic, non-dehydrated animals suspected of renal disease (usually polyuric)
  • assess prognosis of azotemic animals
75
Q

Creatinine clearance rate - endogenous procedure

A

Adequate hydration is confirmed, all urine produced during a given perion (20 min to 24 hrs)

  • metabolism cage or catheterization
  • record volume
  • mixed well and creatinine is measured
76
Q

Creatinine clearance rate - exogenous procedure

A

Same as endogenous, but creatinine is injected into the animal

  • advantage: challenge to the kidney
  • disadvantage: may increase tubular secretion of creatinine, lack of standardization
77
Q

Urinalysis - physical exam

A
  • color
  • clarity
  • USG
78
Q

Urinalysis - chemical exam

A

Reagent strip method

  • pH
  • [protein]
  • [glucose]
  • [ketone]
  • [heme]
  • [occult blood]
  • [bilirubin]
  • [urobilinogen]
  • sediment
79
Q

Voided

A

Samples may have more bacteria, epithelial cells, and leukocytes from distal urethra and genital tract

80
Q

Cystocentesis

A

Iatrogenic hemorrhage

81
Q

Catheterized

A

Epithelial cells, hemorrhage, lubricant, bacteria

82
Q

Off surface

A

Contaminated with a variety of microscopic material

83
Q

Normal urine color

A

Amber

- pale is less concentrated than dark yellow (not always)

84
Q

Abnormal urine color

A
  • red: erythrocytes
  • red-brown: erythrocytes, hemoglobin, myoglobin, methemoglobin
  • brown/black: methemoglobin (from hemo or myoglobin)
  • yellow/orange: bilirubin
  • yellow/brown or yellow/green: bilirubin or biliverdin
85
Q

Horse urine may turn ____ when exposed to snow

A

Brown

- non-pathogenic

86
Q

Urine clarity

A
  • clear-mild turbidity is normal (few epithelial cells, crystals)
  • equine is usually turbid: mucoproteins and calcium carbonate crystals
  • done in fresh, homogenized urine
  • cloudiness: presence of cells, crystals, bacteria, casts, and lipid droplets
87
Q

Solute concentration

A

Dissolved ions and molecules

- Na, Cl, K, Ca, PO4, NH4, urea, creatinine

88
Q

Specific gravity

A

Rate of solution weight/water weight

89
Q

Refractive index

A

Ratio of the speed of light in the vacuum/speed of light in a solution

  • increases proportionally to solute concentration
  • correlates with osmolality
  • suspended particles do not affect meaurement, may make it harder to read refractometer
  • marked proteinuria or glucosuria may hyperestimate [solutes]
90
Q

Is 1.060 the same in the dog and cat?

A

No, type of molecules are different

91
Q

Freezing point osmometry method

A

Freezing point of a solution is inversely related on the concentration of solutes

  • as the concentration increases, freezing-point decreases
  • unit: mol/kg or osmol/kg
92
Q

A lower USG is a worse prognosis until _____

A

Hyposthenuria

- shows there is not a loss of nephron function, is related to ADH function

93
Q

Carnivores have ___ urine and herbivores have ____ urine (unless they are on a milk diet)

A

Acidic; alkaline

  • dogs and cats: 6-7.5 pH
  • horses and cows: 7.5-8.5
94
Q

Aciduria

A

Suggests increased secretion of H

  • acidosis, respiratory and some metabolic
  • hypochloremic metabolic alkalosis
  • hypokalemia: secretion of H increases absorption of K
  • furosamide treatment
  • proximal renal tubule aciduria (if HCO3 is depleted)
95
Q

Alkalinuria

A

Decreased excretion of H

  • urea splitting hydrolysis: spontaneous delayed urinalysis completion, urease containing bacteria
  • respiratory alkalosis
  • distal renal tubular acidosis
  • proximal renal tubular acidosis (without HCO3 is depletion)
96
Q

Proteinuria - physiologic

A

Proteins <68 kD may pass glomerulus

  • usually resorbed, may be in urine
  • dogs have measurable amount of low protein (mostly albumin)
  • Tamm-Horsfall protein –> hyaline cast formation (soluble on pH >7)
97
Q

Proteinuria detection

A
  • strips: detect albumin better than globulins
  • SSA: denaturation of proteins by acids forming precipitation (turbid urine)
  • may help to access some types of proteinuria
98
Q

Tamm-Horsfall protein is secreted by ____

A

Tubules!

99
Q

Prerenal proteinuria

A
  • overflow, overload, and preglomerular
  • increased concentration of small proteins
  • paraproteinuria (light chain proteins –> Bense Jones)
  • hemoglobinuria
  • myoglobinuria
  • postcolostral proteinuria
100
Q

Glomerular proteinuria

A

Damage to glomeruli will allow larger proteins to pass

- usually negatively charged, selective protein loss

101
Q

Tubular proteinuria

A

Proximal tubules are not resorbing proteins

- usually acute renal disease, can be congenital

102
Q

Hemorrhagic or inflammatory proteinuria

A

Exudation of proteins through increased permeability of vessels

  • postrenal (more common)
  • usually see pyuria or hematuria
103
Q

Glucose

A

180mw, resorbed in proximal tubules by Na/glucose cotransport

104
Q

Max glucose transport ability

A
  • dogs: 180-220 mg/dL
  • cats: 290 mg/dL
  • horses and calves: 150 mg/dL (probably lower in mature cattle)
105
Q

Glucose analytical methods

A
  • strip: false neg with ascorbic acid, ketonuria, very concentrated urine
  • copper reduction method: may be used to confirm
106
Q

Hyperglycemia

A

More glucose in ultrafiltrate that can be resorbed

- usually will see hyperglycemia but a transient hyperglycemia with a delay to empty the bladder may mask

107
Q

Renal glucosuria

A

Normoglycemic

  • tubular abnormalities: acquired or congenital
  • acquired: renal tubular toxicosis or ischemia
  • congenital: fanconi syndrome and pure primary renal glucosuria (basenji, norwegian elkhound, shetland sheepdog)
108
Q

Glucosuria will cause

A
  • osmotic diruesis
  • decreased concentration ability
  • increased urine volume
109
Q

Ketones

A

Acetoacetate, B-hydroxybutyrate, acetone

  • not expected in urine of healthy animals
  • may enter thru glomerular filtration or secretion by tubular cells
110
Q

Ketones - analytical method

A
  • strip: false positive with pigmented urine and other compounds
  • only high concentrations of B-hydroxybutyrate
  • acetest table method: blood, plasma, urine, milk
111
Q

Ketonuria

A

Increased metabolism of lipids

  • decreased insulin and increased glucagon
  • may lead to Na and K depletion
112
Q

Heme - strip test

A

Could be hemoglobin, myoglobin, methemoglobin

- intact cells are lysed in the reagent pad

113
Q

Heme - hematest tablet test

A

Confirmatory

- occult blood in feces

114
Q

Heme - heme positive

A

Hematuria

  • hemorrhage in the urinary tract
  • RBCs may lyse if USG is <1.015
115
Q

Hemoglobinuria

A

Intravascular hemolysis after haptoglobin is saturated

- RBCs may lyse if USG is <1.015

116
Q

Myoglobinuria

A

Myocyte damage or necrosis (rhabdomyolysis)

117
Q

Methemoglobin

A

Oxidation of hemoglobin iron in the urine

- oxidative damage causing intravascular hemolysis

118
Q

Bilirubin

A

Not expected in normal urine of mammals other than the dog

  • conjugated bilirubin pass freely thru glomeruli
  • heme converted into unconjugated and then conjugated bilirubin by renal tubular cells
  • strip or ictotest
119
Q

Bilirubinuria

A

Hemolytic states or decreased excretion of bilirubin

  • concentrated urine from healthy dogs frequently produces small bilirubin reaction
  • may be present before hyperbilirubinemia or icterus are detected
120
Q

Urobilinogen

A
  • colorless
  • from degradation of bilirubin in intestine
  • excreted by urine, o removed by hepatocytes
  • reagent strip
121
Q

Increased urobilinogenuria

A

Hemolytic states or hepatobiliary disease

- not clinically relevant

122
Q

Nitrite

A

Gram-neg bacteria reduce nitrate to nitrite

  • strip: false positive with contaminant bacteria
  • positive reaction: presence of gram neg bacteria, significant bacteriuria
  • not clincially relavent due to inconsistency of results
123
Q

Leukocyte esterase

A

Leukocyte in the urine release esterase

- false negative in dogs and false positive results in cats

124
Q

Urine sediments

A

Consistently using the same volume allows a more accurate/clinically relevant semiquantitative result

  • contents not stable, so use fresh urine
  • cells and casts deteriorate
  • crystals can form or dissolve
  • bacteria may die or proliferate
  • mix well before aliquot is removed for centrifugation
  • most sediment findings quantified based on number seen per hpf
  • staining sediments done, but dilution should be taken into account
125
Q

Leukocytes

A

Few is found in healthy animals

- less than 5/hpf

126
Q

Pyruia

A

Increased leukocytes/hpf

  • inflammation of mucosal or submucosal tissues or renal parenchyma
  • infectious or noninfectious
  • knowledge of collection may determine site of inflammation
  • genital tract inflammation
127
Q

Hematuria

A
  • pathological hemorrhage: vascular damage, thrombocytopenia, thrombopathia, vWD, coagulopathies
  • iatrogenic hemorrhage: cystocentesis, catheterization
  • urogenital tract: estrus
128
Q

Urine should be ______

A

Sterile

129
Q

Bacteruria

A

Semiquantified, may proliferate after collection

  • stained air-dried slides to increase accuracy
  • source of sample, presence/absence of pyruia, concentration of bacteria
  • false neg –> urine culture recommended
130
Q

Casts

A

Cylindrical concretions: shape mirrors tubular segment

  • matrix of Tamm-Horsfall mucoprotein and other
  • casts may form from normal sloughing of tubular cells (hyaline or granular): <2/lpf
  • may deteriorate (in alkaline urine)
131
Q

Cylindruria

A
  • hyaline: healthy animals, glomerular proteinuria
  • epithelial or fatty: active tubular degeneration or necrosis
  • granular: tubular degeneration, necrosis or inflammation, healthy animals
132
Q

Epithelial cells

A

From urinary tract mucosa

  • renal tubular, transitional cells, squamous epithelial
  • presesnt in ehalthy animala
  • inflammation can increase release
  • neoplastic cells may be present
133
Q

Crystals

A

Precipitation of salts

- pH may dictate formation or dissolution of crystals

134
Q

Crystalluria

A

Found in healthy animals, increased concentration may suggest presence of some pathological state

  • presence/absence of crystals is not a reliable indicator of presence/absence of uroliths
  • crystalluria is a risk factor for urolith formation
135
Q

Calcium oxalate dihydrate and monohydrate

A

Envelope shape

  • healthy dogs and cats
  • calcium oxalate uroliths
136
Q

Dogs intoxicated with ethylene glycol more commonly have _______

A

Calcium oxalate monohydrate

137
Q

Calcium phosphate

A
  • healthy dogs
  • peristent alkaline urine
  • calcium phosphate urolith
  • infection induced struvite crystalluria
138
Q

Cholesterol

A
  • healthy dogs

- in humnas with excessive tissue destruction, nephrotic syndrome and chyluria

139
Q

Cystine

A
  • hexagonal
  • concentrated acidic urine
  • alkaline urine due to infection or contamination with urease-producing bacteria may cuase the crystal to dissolve
  • dogs and cats with cystinuria (autosome recessive disease)
140
Q

Magnesium ammonium phosphate

A

Struvite

  • coffin
  • normal dogs and cats
  • infection with urease-producing bacteria
  • sterile struvite uroliths
141
Q

Urate

A

Yellow to brown spherules with long irregular protrusions

  • dogs with partial vascular anomalies
  • dogs and cats with ammonium urate uroliths
  • uncommon in healthy dogs/cats
142
Q

Bilirubin

A
  • needle like
  • yellow to brown
  • concentrated urines
  • healthy dogs
  • cholestatic disease in cats, horses, bovine, camelids
143
Q

Calcium carbonate

A

Not described in dogs and cats, healthy in horses and goats

144
Q

Organisms other than bacteria

A

Yeasts, hyphal structures, algae and parasitic structures

- parasitical structures may be due to fecal contamination

145
Q

Lipid droplets

A

Likely from renal tubular epithelium

  • most common in cats (store TG in renal tubular cells)
  • use of lubricants for catheterization
146
Q

Mucous strands

A 
Urogenital secretions (abundant in horses)
- spermatozoa: expected in intact males, occasionally in females after breeding

Clinical Pathology (9 decks)

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