They are generally small, a crossbreed between a dachshund, terrier and whatnot crossed with the ordinary yard dog. They don't bite, unless cornered, provoked or you are just unlucky to be in the wrong place in a big city.
All of these dogs have a degree in that special school that no Western dogs have attended: if one of them seems hostile, just lower a hand to the ground, and the dog will retreat a few meters and generally won't try to approach you anymore. Because it thinks you've picked a stone off the ground, and they all graduated the "beware of the stone" course.
Sometimes a dog will follow you for a few blocks, perhaps thinking you will bring it some food, or just trying to be the man's best friend. Even if you're on a bicycle.
When the stray dogs overbreed, or a rabid fox is caught (rabies was eradicated decades ago, but every year or two some animal crosses the border), the stray dogs in the area are hunted down. This task is usually assigned to hunters' associations (actually, "companies" or "societies"), but not exactly locals, because they'd be the target of mocking for the whole winter. They usually come from two or three villages away.