Some aspects of spaying-related urinary incontinence in the bitch still remain incompletely clarified. Therefore, the aims of the present study were to evaluate the prevalence of the disease among spayed dogs, to detect differences in risk related to the type of surgery, to describe the characteristics of incontinent bitches, to assess the influence of age at surgery on the onset of incontinence occurrence, and to assess the effectiveness and long-term side effects of oestrogen therapy in affected bitches. Among 750 bitches submitted to ovariectomy or ovariohysterectomy, those showing spaying-related urinary incontinence were evaluated. Oestrogen replacement therapy consisted of administering an effective dose followed by an individual maintenance dose. The results showed that the disease occurred in 5% of neutered bitches, the type of surgery did not affect the disease occurrence, affected bitches frequently represented large or giant breeds or large-size mongrels, the body weight of the affected bitches at surgery was often ≥ 20 kg, the disease seems to be associated with tail docking, the age at surgery influences the onset of incontinence, with earlier occurrence in older bitches, and that a strong co-operation between owners and veterinarians is necessary to achieve successful response to oestrogen replacement therapy. Long-term administration seems to be unrelated to oestrogenic side effects.Key words: Bitch, spaying, urinary incontinence, oestrogen therapy Urinary continence results from the combined effect of anatomical and physiological factors leading to normal urinary bladder storage, bladder neck