Treatment of urethral sphincter mechanism incompetence in 11 bitches with a sustainedrelease formulation of phenylpropanolamine hydrochloride

Between 1995 and 1999, urethral sphincter mechanism incompetence was diagnosed in 11 bitches. They had been treated with phenylpropanolamine hydrochloride at the recommended dose rate, but had shown no response or had become refractory to treatment. They were treated with phenylpropanolamine hydrochloride in a sustained-release formulation combined with diphenylpyraline hydrochloride. The urinary incontinence resolved fully in six of the bitches, two of which remained continent after the treatment was withdrawn; two showed a marked improvement on daily treatment, but the other three bitches failed to respond and underwent colposuspension.