Page 884 - Small Animal Clinical Nutrition 5th Edition

Chapter
44

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Canine Silica Urolithiasis:

Causes, Detection, Treatment

and Prevention

Carl A. Osborne
Jody P. Lulich

Lisa K. Ulrich

“There is a difference between unanswered questions
and unquestioned answers.”
Carl A. Osborne

tals are so small that they can only be seen through a micro-
TERMINOLOGY scope. The term cryptocrystalline refers to the fact that the
crystals are too small to be seen by light microscopy. The des-
The name silicon (Si) is derived from the Latin word “silicis” ignation as amorphous (without shape) refers to the orientation
meaning flint. Silicon is a naturally occurring nonmetallic ele- of SiO 2 molecules in a random or non-periodic pattern.
ment. When combined with oxygen, Si forms SiO and is Amorphous minerals are also called mineraloids. Most silica-
2
called silica or silicon dioxide. The term silicate is a noun used containing uroliths removed from dogs are composed of amor-
to designate a salt derived from silicic acid (as in aluminum sil- phous silica.
icate and magnesium trisilicate).The term silicon should not be Inorganic crystalline silica is the basic component of sand,
confused with silicone. Silicone refers to any of a group of syn- quartz and granite. Microcrystalline silica is found in quartz,
thetic resins, oils, greases, plastics, etc. in which the carbon ele- chalcedony (agate, onyx, etc.) and chert (flint, jasper, etc.).
ment has been replaced with silicon. Amorphous silica is found in glass, opal and diatomaceous
earth.
Inorganic Silica
Inorganic silica, whose basic formula is SiO , occurs naturally Organic Silica
2
in crystalline, microcrystalline, cryptocrystalline or amorphous Although silicate and silica minerals constitute more than 90%
forms. The designation SiO as crystalline refers to the orien- of the earth’s crust, they occur in very low concentrations in
2
tation of silicon molecules in a fixed, orderly and repetitive pat- most animals. The low quantities of silica in most animals may
tern resulting in a characteristic shape. Crystals reflect internal be attributable to the low solubility of silica in all but a very few
order.The term microcrystalline refers to the fact that the crys- naturally occurring waters. In contrast, plants often contain