Neodymium:yttrium-aluminum-garnet laser ablation of a urethral web to relieve urinary outflow obstruction in a horse.

An 8-year-old Hanoverian gelding was examined because of urine dribbling and urethral obstruction. Mild proprioceptive deficits of the left hind limb were evident during neurologic examination. Ultrasonography per rectum revealed dilatation of the pelvic portion of the urethra. Endoscopy of the urethra revealed 2 webs of tissue: 1 was located 10 cm proximal to the external urethral opening; the other was located 65 cm proximal to the external urethral opening and prevented passage of the endoscope into the urinary bladder. The mass was ablated with a neodymium:yttrium-aluminum-garnet laser, using a transendoscopic noncontact technique. On follow-up examination 6 months after laser surgery, an endoscope could easily be passed into the bladder, and no urethral web was seen. The horse was able to void a stream of urine but continued to dribble urine intermittently. The proximal location of the urethral lesion in this horse would have made use of traditional surgical methods problematic, whereas transendoscopic laser photoablation was easy and effective.