Vetoquinol - Propalin Syrup for Dogs 40mg/ml - 30MLOverview Propalin Syrup 40mg ml is a veterinary prescription medication developed by Vetoquinol for the management of urinary incontinence in dogs. It contains phenylpropanolamine hydrochloride, a sympathomimetic agent that increases urethral sphincter tone, helping to prevent involuntary urine leakage. Propalin is especially effective in spayed female dogs (ovariohysterectomised bitches) and is intended for long term use under veterinary supervision.