Urinary Crystals and Casts

Question 1

Answer 1

Struvite
(Mg Ammonium phosphate, triple phosphate)
“coffin lids”
Neutral to alkaline pH >7

Question 2

Answer 2

Bilirubin crystals form from conjugated bilirubin (water soluble)
Acidic pH<7

Question 3

Answer 3

Calcium Carbonate
Large spheroids with radial striations. Colorless to yellow-brown
Usually alkaline pH >7

Question 4

Answer 4

Amorphous crystals
Finely granular material. composed or urates, phosphates, or xanthine
Phosphates pH>7, Urates pH<7

Question 5

Answer 5

Calcium oxalate dihydrate
Colorless squares whose corners are connected by intersecting lines (resembling an envelope)
pH <7

Question 6

Answer 6

Calcium oxalate monohydrate
Vary in size and may have a spindle, oval, or dumb-bell shape. “Hemp seed” or “picket fence”
Neutral or acidic pH<7

Question 7

Answer 7

Ammonium biurate
Generally appear as brown or yellow-born spherical bodies with irregular protrusions (thorn-apples)
Usually acidic to neutral, rarely alkaline

Question 8

Answer 8

Cystine
Flat, colorless plates and have a characteristic hexagonal shape
Usually neutral to acidic pH <7

Question 9

Answer 9

Uric acid
Variably sizes, small to medium with some large forms. Yellow, red-brown, rarely colorless
Acidic pH<7

Question 10

Answer 10

Calcium Phosphate
Medium to small, colorless. Blunt ended needles or prisms, often in rosettes
Usually neutral or alkaline pH>7

Question 11

Answer 11

Tyrosine
Small crystals (appear large because they are in aggregates). Fine colorless to brownish needles. Indicate severe liver disease (rare in animals)
Acidic pH <7

Question 12

Answer 12

Hyaline

Question 13

Answer 13

Cellular Casts

Question 14

Answer 14

Granular Casts

Question 15

Answer 15

Fatty Casts

Question 16

Answer 16

Waxy Casts

Question 17

Answer 17

Red blood cell casts