I use to walk 3 dogs at the same time a golden retriever, Yorkie, and jack-a-poo.
I would put them all on their own leash.
I would put them on my left side and wrap the leash in my left hand about two times around (depending on the length) and drape the excess kinda infont of me not too loose and hold the rest in the right hand. I would control them with my left hand and not give them too much lead. If they pulled I would pull back and say back. It took about 2 weeks but they loved walking together.
__________________  Proud Mom of Daisy and Pixie |