Abstract

Crystalluria is a common finding in Asian elephants, but urethral calculi and uroliths are infrequently reported.^2,3 Parameters have not been established to determine if urine crystals indicate pathogenesis.¹ In this study, 91 urine samples from 5 female Asian elephants were retrospectively analyzed for crystal occurrence and type. Overall, 79% of samples contained crystals. Types identified were calcium carbonate (58%), calcium oxalate (17%), struvite (17%), and amorphous (58%). Two cases of urolithiasis were diagnosed postmortem. Case 1, a 49-yr-old, had a 6.9-kg urolith (27.9 cmx12.7 cm). Superficial urolith analysis was 100% calcium carbonate. Of 25 urine samples from case 1, 15 contained crystals; 87% were calcium carbonate. Case 2, a 53-yr-old, had a 10.7-kg urolith (29 cmx23 cm). External analysis, sectioning, Faxitron scan, spectral analysis, and CT scan were performed at the Minnesota Urolith Center. Stone composition was 100% calcium carbonate. Of 36 urine samples from case 2, 30 contained crystals; 96% were calcium carbonate. No significant differences between type, frequency, and quantity of crystals were present between urolith and non-urolith groups, indicating no predictive value between presence of urine crystals and pathogenic urolithiasis; however, in the urolith group, there was a correlation between crystalluria type and urolith composition, indicating urine crystal type may be a useful indicator of stone composition if one is identified via diagnostic imaging.

Acknowledgments

The authors would like to acknowledge the Minnesota Urolith Center for performing urolith analysis, Dr. Steven Scott, Director of Veterinary Care, for his compassionate, dedicated service to The Sanctuary’s elephants since 1995, and the elephant caregivers, whose excellent daily care makes individualized veterinary care possible.

Literature Cited

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2.  Osborne C, Albasan H, Lulich J, Nwaokorie E, Koehler L, Ulrich L. Quantitative analysis of 4468 uroliths retrieved from farm animals, exotic species, and wildlife submitted to the Minnesota Urolith Center: 1981–2007. Vet Clin North Am Small Anim Pract. 2009;39(1):65–78.

3.  Thongtip N, Lorsanyaluck B, Sukmak M, Chaichanathong S, Thengchaisri N, Sunyathitiseree P, Wajjwalku W. Surgical removal of urethral and bladder stones in female Asian elephant (Elephas maximus) by episiotomy and urethrotomy. Thai J Vet Med. 2013;43(3):375–382.