The east bank trail extends along the river Cong from the stone bridge at Ashford castle to the village of Cong. This narrow, moss-coverd footbridge offers foot traffic (or the brave bicyclist) a means to cross to over to the other bank. It can easily support the weight of a person. It is not intended to be crossed on horseback. Or even pony-back, for that matter.
Fortunately, a ford is just upstream from the bridge. It is close enough to the bridge that a person might walk across the bridge, reins in hand, while the horse (or pony) wades through the river.
Then again, a person attempting this might end up going for an unexpected swim. As might a bicyclist who has a tire slip while attempting to ride across.
Paths lead north along the river bank, west over the footbridge, or to the south.