There is perhaps worse than off-leash: on a bloody 16 feet retractable leash, with the dog on one side of the road, and the owner on the other side... So called "retractable", because you cannot pull anything.
A friend suffered a bicycle crash and killed a dog like that. I can see from my place all the time the same situation waiting to happen, with women busy chatting on one side, and not caring at all about where the dog goes. When I had to walk the dog of a former girlfriend on a road/street side, I always took the short, fixed leash, and in places where room was scarce, I even kept my second hand further on the leash to be able to shorten it quickly if needed.
Just a couple of days ago, a bit different situations. I was cycling uphill on a small road, and there was a woman (it's almost always a woman, in fact) with a dog at her feet on the right of the road. I prepared to move a bit to the left to give them space while taking over. But the dog started coming to me (not aggressively), and the woman let the leash unroll, and unroll, and unroll. She never stopped it, but started yelling: not at the dog to call it back (which has a dubious success rate in general but shows a little bit of conscience at least), but at me! She was telling me to slow down, that I was crazy and dangerous. I said it was uphill, and I suck at climbing, so I was cycling at the ridiculous speed of 5 mph (yes, five)... And I was now on the opposite side of the road. It's a very bad idea to yell at me, it makes me completely snap, so the result was not what she expected.
Coming back to off-leash, I was bitten in the calf while riding last year by two dogs (so far dogs had only gone for my trousers, but this time they went through the trouser, through the sock, and through the skin). The owner was standing 10 yards away, he didn't do or say anything. He didn't give a damn. In the little "discussion" had with the cretin, he kept claiming his dogs do not bite... while they were biting and pulling my trouser again... At no point he tried to regain control of his dogs. As it should be done, I reported it to the Mayor, who MUST take measures: here, there is no immediate death penalty for such behaviour, but the Mayor MUST make sure the dog should first be sent to a vet for behavioural examination. She didn't do anything.
At my place, there are plenty of dogs loose all day long. The (French) law is lax, but even the few restrictions are never enforced. They shit and dig holes in people's open gardens, they occasionally attack and sometimes kill other people's pets (dogs and cats). Then you have shepherds dogs, who attack cyclists and occasionally pedestrians, even on public roads (and it's not a matter of protection, these bastards generally attack people in the back, after they have passed by); often farmers' dogs haven't been trained at all, or in the case of livestock farmers only trained to one purpose and the relation with humans was not part of it. When I was living in another country, dogs were never loose: either in a fenced yard, or on a leash ; whether they were pet dogs, shepherds dogs, sledge dogs or whatever type of dog and dog owner you may imagine. But over here people will tell you this is impossible. Gee...
There are plenty of dogs these days. Cats are even worse, it is a proliferation (their number was multiplied by 2 or 3 in a few decades, IIRC), and due to their nature, they are even less kept under control. Luckily, they are also less a danger to humans, but they are worse about gardens, because contrarily to dogs, they ignore fences :-)
It's like everyone wants to own a pet for the fun side, but the negative externalities are for others to undergo. Of course I don't do justice to the owners who care and pay attention, they do exist :-) but of course the others are more noticeable.