Here in Uruguay it is fairly normal to see free roaming dogs cruise the streets, roads, or fields. From my travels in South America this seems to be the norm. Rule to remember: if you feel threatened by a dog in your route, grab a rock and pretend like you are going to throw it at the beast...or if you can't find a rock, just pretend that you have something to hurl. The animals react (however in the States the dog would look at you as if to say, "Are you challenged?").
But here in parts of this country I have come across some classic perros. Whether it be for their characteristic faces, actions, or locations. For example, what was this guy doing??