The Canids (2013)

From publisher blurb:

No species has a history so integrated with humanity as the common dog, and no race is as interspersed into the lives of other races as the Canids. For as long as records have been kept, canids have been around, though no origin story is told for them, and no god claims them as their own. Some theorize that they were created to live in tandem to other races, but if that is the case, by whom? Why would they regularly face off on opposite sides of the battlefield? Most likely, the canids evolved into a niche in society that was easily filled, and advantageous to enter. Canids are almost always found living alongside a much larger encampment of another race, and over time they have developed individual peculiarities that compliment the foster race they are bonded to.