Holmium:YAG laser lithotripsy for urolithiasis in horses.

BACKGROUND Laser lithotripsy has been used as an alternative to surgical removal of uroliths. OBJECTIVE To describe the procedure and efficacy of laser lithotripsy for removal of lower urinary tract uroliths in horses. Additionally, the ultrastructure and the differences in mineralogy and microstructure from 1 successful and 1 unsuccessful laser lithotripsy case are described. ANIMALS Six client-owned horses with 7 episodes of naturally occurring urocystoliths, urethroliths, or both. METHODS Retrospective study of all horses treated between 2006 and 2008 by laser lithotripsy. All horses were sedated followed by laser lithotripsy. Quantitative urolith analysis was performed in all cases. Ultrastructure and microstructure analyses were performed on uroliths from 2 horses. RESULTS Procedural success was achieved in 5 of 7 laser lithotripsy procedures. No complications occurred as a result of laser lithotripsy. One horse developed uroabdomen likely as a result of manual lithotrite disruption of the bladder after failure of laser lithotripsy. There were differences in microstructure between 1 urolith that was successfully fragmented by laser lithotripsy and 1 urolith that was resistant to laser fragmentation. CONCLUSIONS AND CLINICAL IMPORTANCE Laser lithotripsy is an effective procedure for removal of some urocystoliths, urethroliths, or both in horses.