First off- you shouldnt add in dog food when you name a price. Like a used car you sell it for what it is worth not how much you spent on gas while owning it.
I don't really see the correlation. First off, an automobile depreciates over time...a good hunting dog does not. Secondly, when you buy fuel for a car you recognize an immediate return for your investment (ie. you get to go from here to there) so your not necessarily loosing your money.
Feed is a necessary component (and cost) of raising a dog. Why would that not be considered a recoverable expense? Not necessarily with dogs but with ANYTHING I might sell, I always consider my cost.
I guarantee you, the price paid for a package of ground beef at the grocery store has cost associated in it for the expense of feeding that cow.
Whether it's blood, sweat and tears or cold hard cash, you've gotta pay to play...
We have a winner. Good post.