Urethral Sphincter Mechanism Incompetence (USMI)

The focus of this chapter is on animals in which urinary incontinence is the primary sign, although other urinary abnormalities may be present in some cases. Urinary incontinence is a common problem in dogs (around 5% of adult bitches; Forsee et al., 2013), with many affected animals managed medically in first-opinion practice, often after only minimal diagnostic investigations. This chapter looks at anatomy and physiology, investigation, differential diagnosis and different conditions. Practical tips are included. Operative techniques: Colposuspension; Cystourethropexy; Prostatopexy; Vas deferensopexy; Urethral submucosal collagen injection; Ureteroneocystotomy; Ureteral reimplantation.