Heres a really good way to fix your problem, you might think that it wont work I'v done it with a perfect outcome. Take your bigger dog and put the leash on him/her and take the other end and connect it to the smaller dogs collar and while the little...

Put a fence between them to introduce them slower. they'll worm up to eachother once the dominance factor has set in with them. Till then they will fight its nature, your putting a dog in a territory of another its going to happen. just reward them w...