Evaluation of long-term effects of endoscopic injection of collagen into the urethral submucosa for treatment of urethral sphincter incompetence in female dogs: 40 cases (1993-2000)

OBJECTIVE: To evaluate long-term success of endoscopic injection of collagen into the urethral submucosa in female dogs with urinary incontinence caused by urethral sphincter incompetence. DESIGN: Retrospective study. ANIMALS: 40 incontinent female dogs. PROCEDURE: Medical records were reviewed for outcome and other results for dogs in which a cystoscope was passed into the urethra for deposition of 3 collagen deposits into the submucosa. RESULTS: 27 (68%) dogs were continent for 1 to 64 months (mean, 17 months) after the collagen injection. In another 10 dogs, incontinence improved and in 6 of these dogs, full continence was regained with administration of additional medication. In 3 dogs, incontinence was unchanged. As long as 12 months after injection, there was a deterioration in the initial result in 16 dogs, after which their condition stabilized. Mild and transient adverse effects developed in 6 (15%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Long-term success of endoscopic injection of collagen was satisfactory. Relapse of incontinence might be caused by flattening of the collagen deposits rather than resorption of the collagen.