The association between acquired urinary sphincter mechanism incompetence in bitches and early spaying: a case-control study.

A case-control study was conducted between December 2005 and August 2006 in London (1) to estimate the strength of association between early ovariohysterectomy (spaying) and urinary incontinence (sphincter mechanism incompetence), (2) to identify other risk factors for incontinence, and (3) to assess any implications of incontinence on the owner-pet relationship. Cases were defined as bitches that developed incontinence after spaying and were treated, and the controls comprised continent spayed bitches. Questionnaires from 202 cases were compared to 168 controls, and analysed using multivariable logistic regression. No significant association between early spaying and incontinence was detected although there was a tendency that early spayed bitches were less likely to be incontinent. Docked bitches were 3.8 times more likely to be incontinent than undocked bitches; bitches weighing over 10 kg were 3.7 times more likely to be incontinent than smaller dogs; and older bitches were more likely to be incontinent (OR=3.1-23.8) than younger animals. Some owners were found to have a negative attitude towards incontinence.