I've noticed on my rides...when I see an unleashed dog....it's un-nerving to me because I don't know if they are under voice control or not, the simple act of the responsible owner putting their hand on the dogs collar as a 'just in case' is very reassuring for me....and that's all I need.... same for when they are leashed...for the owner to just lead the dog in.

(most) Dogs just do not like helmets.....even the most controlled dog can get nervous and act in a very unexpected manner for all involved.

For the safety of everyone involved (and the dogs own security) I would wish that everyone show that the dog is under control by a leash or a temporary grip of the collar when passing others.