Safety and Efficacy of Transurethral Laser Lithotripsy and Percutaneous Laser Lithotripsy in 41 Dogs with Lower Urinary Tract Stones

Jin Shigemoto^*Mitsunobu Kawazu

• Oji Pet Clinic-Tokyo Animal Minimally Invasive Center, Tokyo, Japan

Objective: The clinical application of transurethral laser lithotripsy (TUL) for lower urinary tract stone removal in dogs is constrained by factors such as body weight, stone size, and stone number. This study evaluated the safety and efficacy of TUL and percutaneous laser lithotripsy (PL) in cases where TUL alone was not feasible. Study Design: Retrospective study. Animal population: Forty-one dogs (24 males, 17 females) were included between June 15, 2017, and January 26, 2023. Among them, 13 males were castrated and 14 females spayed. Method: TUL was performed using a holmium:yttrium-aluminum-garnet (Ho:YAG) laser, an 8.5Fr flexible ureteroscope, and a 9.5Fr rigid cystoscope for urethral and bladder stone fragmentation. PL was conducted using a Ho:YAG laser in combination with percutaneous cystolithotomy (PCCL). Results: TUL was performed in 34 dogs, including 22 males (64.7%) and 12 females (35.2%). Laser lithotripsy was categorized by endoscope type and stone location. Of these, 33 dogs (94.1%) completed the procedure, while one male (2.9%) required conversion due to excessive bleeding. PL was performed in seven dogs (two males, 28.5%; five females, 71.4%), all of whom (100%) This is a provisional file, not the final typeset article completed the procedure without conversion. Complications from laser lithotripsy occurred in five males (12.1%) of 41 dogs. Conclusion: TUL is a minimally invasive urethral procedure, but its feasibility is limited in underweight dogs where endoscope insertion is impractical. Clinical Significance: When TUL alone is unviable, combining it with PL provides a safe and effective laser lithotripsy approach for bladder and urethral stones, regardless of the dog's weight or sex.