I have absolutely no problem with running 2 dogs at once, just a word of warning, I would definately buy a more sturdy harness, such as the coastal wagon harness, it buckles under the tummy, that way they can't slip out. Also buy a strong coupler instead of the little cloth thing they give you. We got our harnesses, and springer from
Dog Harnesses at Dresslers Dog Supplies Store Entrance if you scroll down to the bottom of the page it's the last harness, and the springer is right under it. We just got the coupler at a local pet store, I use the leather couplers with the bigger clasp. Hope this info helps.