Cholesterol
Flat
colorless plates
with corner notch (“Utah”)
- -acidic, neutral urine
- *may be normal in dogs & cats
Calcium carbonate
Tiny
colorless
spheres or dumbbells
- -alkaline/neutral urine
- *common (normal) in rabbits, cows, and horses
Calcium oxalate
Small
colorless
envelopes, dumbbell, & ring forms
- Dihydrate = can be normal (esp. plant diets); also in ethylene glycol toxicity
- *MONOhydrate = Specific for EG tox!
Cystine
Flat
colorless
hexagonal plates
–acidic urine
Leucine
Yellow
spheres
with concentric striations
–acidic urine
Phosphates (ammonium, Mg)
3-6 sided
colorless prisms
**can be normal in dogs (± cats)
or
**associated with calculi
Phosphates (Calcium)
Amorphous or long thin prisms
** common (normal) in dogs
Tyrosine
Fine,
colorless or yellow needles
arranged in sheaves or rosettes
–acidic urine
Urates (amorphous Ca, Mg, K)
Fine
yellow-red
amorphous granules
–acidic urine
Urates (ammonium) / biurate
Yellow-brown spheres (“thorn apples”)
-alkaline urine!
**R/O disorders of ammonia metabolism
(shunts, liver mass)
**can be normal in Dalmatians
Bilirubin granules/clusters
evaluate liver for cholestasis!!
Uric Acid crystals
- common in Dalmatians, +/- other dogs.
- associated with altered purine metabolism
(gout in man)
Sulfa crystals
consider drugs for bizarre, colored crystals
