Like all rulesets that people call "tightly focused", Dogs really isn't all that tightly focused. It can be used, really, for any sort of game in which:
a) The players roam from location to location resolving conflicts
b) They are invested with the power and authority to do so
c) The way the conflicts are resolved is entirely open-ended
d) The conflicts are based around sin, corruption, decadence, and so on
Which means that, really, it would be almost criminally easy to rejig the system to run:
- Dogs in the Grimdark Future: The players are inquisitors travelling around a subsector of the Imperium in the year 40,000, rooting out daemonic influence
- Dogs in Canaan: The players are biblical judges in the Deuteronomic era, travelling from village to village, fighting against idolatory, oppressive kings, and the collapse of social order
- Shire Reeves in the Vineyard: The players are sheriffs or shire-reeves responsible for keeping the peace in a shire in Anglo-Saxon England
- Dogs in the West: The players are US Marshals in the American West - Clint Eastwood eat your heart out
- Inu in the Budouen: The players are samurai charged by the local Daimyo with law and order for a frontier province
And so on and so forth.