Hi there,
Fortunately, there are many. Even the administration of high phytoestrogen herbs like Alfalfa tincture or soy isoflavones can provide enough of an estrogenic effect to normalize sphincter contraction.
Other high phytoestrogen formulas include Xiao Yao San (Rambling Ease Powder) and Bu Zhong Yi Qi Tang (Ginseng and Astragalus). The latter also helps improve cognition and reduce the depth of sleep, allowing the dog to wake and ask to go out instead of just urinating on their bed.
Lastly, for some dogs, we've found Sang Piao Xiao San (Mantis Egg-Casing Powder) to be helpful. It works even better if a little Alpinia (Yi Zhi Ren) is added, say to make up 10% of the formula. That formula also improves cognition and also promotes increased sphincter tone through its high calcium content. If it works, you may want to supplement the dog with calcium.
Hopefully that gives you something to look through and try. There's a certain interchangeability here, but you may find the symptom description of the dog fits one of these formulas more than the others.
Good luck!
Steve