Vira-latas are defined in two ways. First, a vira-lata is a mixed-breed dog or cat. Secondly, its a dog or cat that has been abandoned by its owner and thrown out on the street to fend for itself. There’s probably no real estimate of how many vira-latas there are on the streets of Brazil, but the number must be astoundingly high. The formal term for them, as used by veterinarians, is SRD, or sem raça definida (without a defined breed).
The name derives from the fact that when they are abandoned, they end up searching out food and are often found digging through trash and turning over latas (cans, ie, of canned food). Vira means turn or turn around/over, from the verb Virar. Seeing them so often and in such decrepit conditions, literally just bones and hair, is a sad sad sight. Sometimes their owners just decide one day to throw them out because they tire of caring for them or because they can’t afford them anymore. Fortunately there is at least a little hope on the horizon in the sense of NGOs that care for them and try to get them adopted.
I’m sure the side-view of this vira-lata from Brazil would show merely its bones.
Eyes On Brazil 
Que amor de cachorrinho! Uma pena em ver tantos cães sem lar. Isso, infelizmente, é bem comum. Deveriam haver mais grupos de apoio e defesa ao animal, assim como a SUIPA.