Identification of calcium oxalate monohydrate crystals by X-ray diffraction in urine of ethylene glycol-intoxicated dogs

Urine sediments of dogs with experimentally induced ethylene glycol poisoning were examined by light microscopy and X-ray diffraction. Massive calcium oxalate crystalluria was observed in all poisoned dogs. By light microscopy, the frequency with which six-sided hippurate-like prisms and envelope forms of calcium oxalate dihydrate occurred was approximately equal. The hippurate-like crystals were shown to be calcium oxalate monohydrate by X-ray diffractometry.