'You should not have to modify any part of your behaviour to avoid scaring an animal'..
Try that in a car on a road with a horse and see where that gets you...
It's a little thing called common courtesy, manners, consideration for others.
Read my post again - if you are running toward a dog owner who is FACING you and can see you and prepare and call their dog back, put it in a stay, put on a lead or put the dog already on a lead in a safer position - fine, but do give them the chance to do that... you know, look to see if they are struggling and slow up a bit, go around rather than close...
If you are running up BEHIND someone who therefore cannot predict your sudden appearance - yes, damn straight, go around, slow the fuck down have some bloody manners.
If you don't want to take the time to not scare my dogs (which on the whole are on leads if I am walking them)... not sure I'll bother to take the time to ensure my dogs don't scare the shit outta you..
If you run up behind one of my dogs and scare them the reaction is likely to be a 40kg dog who can stand 6foot on her hind legs leaping up and barking like fuck - she won't make contact, she'd be on a 4ft lead, but she will make you shit yourself sufficiently that you fall over or swerve into the road or into the bushes...
Sharing public spaces goes both ways - dog owners should keep their dogs under reasonable control (but dogs barking out of fear and being startled is not unreasonable), but joggers and cyclists should ALSO be polite and courteous, slowing down, calling out that they are approaching from behind, going wide and giving space - these are reasonable adjustments to make.
So yeah I'll say it again if you don't want to make such adjustments and alter your behaviour to be courteous to other members of the public, go do your running in a private safe space where you don't need to do these things.