In the Warhammer universe the Dogs of War have undergone significant changes over the editions. Currently the were last a "legal" army under the 6th edition rules for Warhammer.
With the advent of the Age of Sigmar rules from Games Workshop there are no rules for Dogs of War as they previously existed.
Dogs of War are divided into "regular troops" as well as Regiments of Renown. Regiments of Renown are special, characterful units that have additional rules and typically greater cost in terms of points.
Pre 5th Edition
Prior to 5th edition the term Dogs of War was used by Games Workshop to denote mercenaries in a general sense. White Dwarf throughout its run featured advertisements with minis under the title Dogs of War, but were not a Dogs of War army as such. Examples of such advertisements can be found here.
5th Edition
Information for: 5th edition Dogs of War

6th Edition
In the Warhammer universe the Dogs of War have undergone significant changes over the editions. Currently the were last a "legal" army under the 6th edition rules for Warhammer.
With the advent of the Age of Sigmar rules from Games Workshop there are no rules for Dogs of War as they previously existed.
Dogs of War are divided into "regular troops" as well as Regiments of Renown. Regiments of Renown are special, characterful units that have additional rules and typically greater cost in terms of points.