Ultrastructure of selected struvite-containing urinary calculi from dogs.

Abstract

OBJECTIVE:

To elucidate the ultrastructural details of struvite-containing urinary calculi from dogs.

SAMPLE POPULATION:

38 specimens were selected from a collection of approximately 13,000 canine urinary calculi: 18 of these were composed entirely of struvite, and 20 consisted of struvite and calcium phosphate (apatite).

PROCEDURE:

Qualitative and quantitative analyses of specimens included use of plain and polarized light microscopy, x-ray diffractometry, scanning electron microscopy with backscattered electron imagery, x-ray fluorescence scans, and electron microprobe analysis.

RESULTS:

4 textural types were recognized among struvite calculi, and 4 textural types of struvite-apatite calculi were described. Evidences of calculus dissolution were described from 4 calculi studied.

CONCLUSIONS:

The presence of small, well interconnected primary pores in struvite-containing urinary calculi from dogs appears to be a significant factor in determining the possible interaction of calculi with changes in the urine composition. The progress of dissolution from the calculus surface to the calculus interior appears to be largely affected by the primary porosity originally present between crystals forming the calculus framework. Apatite was observed to be more resistant to dissolution than struvite.

CLINICAL RELEVANCE:

The prevalence of fine concentric laminations having low porosity, and the common occurrence of apatite among struvite-containing urinary calculi from dogs may be 2 reasons why the efficacy of dietary and medicinal manipulations in dissolving urinary calculi is greater among cats than it is among dogs.

• Authors: R A Domingo-Neumann, A L Ruby, G V Ling, P S Schiffman, D L Johnson
• Journal: American journal of veterinary research (Am J Vet Res) Vol. 57 Issue 9 Pg. 1274-87 (Sep 1996) ISSN: 0002-9645 [Print] United States
• PMID: 8874719 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium Phosphates
• Magnesium Compounds
• Phosphates
• alpha-tricalcium phosphate
• tetracalcium phosphate
• calcium phosphate, monobasic, anhydrous
• calcium phosphate
• Struvite
• calcium phosphate, dibasic, anhydrous

Topics

• Animals
• Calcium Phosphates (analysis)
• Cat Diseases
• Cats
• Dog Diseases
• Dogs
• Electron Probe Microanalysis
• Magnesium Compounds (analysis)
• Microscopy, Electron, Scanning
• Phosphates (analysis)
• Polarography
• Spectrometry, X-Ray Emission
• Struvite
• Urinary Calculi (therapy, ultrastructure, veterinary)
• X-Ray Diffraction