What is urethral sphincter mechanism incompetence (USMI)?

Urethral sphincter mechanism incompetence (USMI) is primarily recognized as the most common cause of urinary incontinence in adult dogs, especially in spayed females. This condition occurs when the urethral sphincter is unable to maintain closure during periods of increased abdominal pressure, leading to involuntary leakage of urine. It typically develops in middle-aged to older dogs and is significantly prevalent among spayed females due to hormonal influences affecting the integrity of the urethral sphincter.

While the assessment of canine urinary incontinence might involve various conditions affecting both male and female dogs, USMI itself is notably the leading cause of this issue in adult females. Understanding this mechanism is crucial for veterinary practitioners and pet owners alike, as it can guide effective management strategies, including the potential use of medications, hormone therapy, or surgical options aimed at improving bladder control.

The other options either misstate the demographics affected by USMI or misidentify its prevalence. For instance, while it can occur in males, it is certainly not a rare condition in them; it is predominantly a concern for spayed females. Furthermore, USMI is unlikely to be purely linked to puppies, nor is it non-existent in spayed females, where it is most