Alan Dean Foster 
Light-Years Beneath My Feet 

Abducted by aliens to be sold as pets in a more civilized part of the galaxy, earthlings Marcus Walker and a scruffy dog named George (speech-enhanced to increase his market value) have managed to escape their captors. Walker loves being humankind’s first galactic traveller – until he remembers he hasn’t a clue where his home is or how to get there. So the erstwhile commodities broker becomes a chef, whipping up delicacies for demanding alien palates. Of course he never imagined that the way back to Chicago would involve swapping his easy-living adopted planet for an all-out, age-old war many parsecs away. But hey, it’s all for a good cause, h has George and their two fellow escapees for company, and what else is there to do, besides avoid nasty aliens? Plenty, it turns out.