Not a dog owner - but there have been a few posts on FB. Where UNleashed dogs have attacked leashed dogs - or people.
It is the owner, not the dog, who needs socialising.
Dog shit is a problem spreading disease to urban caracal. And after heavy rain, a problem in the sea, contaminating fish, and unsafe for swimming.
Dogs are allowed on one side of Silvermine dam, where people swim - so that water is also not quite as clean as it could be.
There are already National Parks which allow dogs only in parking and camping areas and the vicinty of visitor centers, not on trails.
The Smithsonian Institute has an environmental research center, https://serc.si.edu/ , a few miles from me with about 4 miles of trails through the woods, No pets allowed.
You enter the property past a guarded gate house, and have to stop to state your business. After telling them you’re hiking, they ask if you have any pets with you.
No poop/bags of poop(what is with these people?) along the trail, and no unleashed dogs. It’s wonderful!
I love dogs, but after 4 years in County parks I’ve come to not care much for most dog owners.
Well, good news, I suppose, depending on one’s point of view.
That’s the way to do it! I also love dogs, grew up with them and had my own in previous years, and I understand the desire of dog owners to provide an enriching experience for their beloved pets, and to enjoy their company on hikes, or to feel a greater sense of security from a dog scaring away wildlife or even people. But, I often wish there were separate trails (or days of use?) for those of us who would rather hike/walk without their exhuberance and excrement, and who are there to get to see the wildlife.
In my experience, dog owners frequently exempt themselves from local leash laws and from picking up after their pets. They also often seem to assume that others just need to meet their dog and see how friendly it is, and that will eliminate any issues. A dog walker’s first words to me are usually “don’t worry, he’s friendly”, as if anyone who doesn’t welcome the unleashed dog charging at them is simply afraid of it. They don’t seem to get that being greeted by friendly dogs too often leaves me covered in their fur, slobber and scent, and often wet and muddy from their lake or river play time, and I don’t want that (and that’s ok!). Equally a problem is the frustration of losing whatever I was photographing, or having all surrounding wildlife disappear from the area along the rest of the trail. Dogs who see me crouching, engrossed in trying to get pictures will bark like crazy at my apparently concerning behavior. I understand, but, I just wanted to have a peaceful walk.
There are plenty of rules where I live for trail use, but an awful lot of people don’t respect those rules, so they’re pointless. I just would like an equal chance at enjoying my version of a nature hike - the kind where I get to experience and hopefully even photograph the wildlife that lives there. I think it’s wonderful that you’ve got a place to go where you get to be free of such encounters.
My hiking group is Fynbos Ramblers. We were kneeling around a flower taking photos - when a professional dog walker came with a bunch of dogs. Who bounded over to SEE and trampled our flower 
Keep walking. Maybe next time. She came along with a second bunch of dogs while were still on that trail, that morning.