Well, my dog food calculations went awry, as Richard Reiss pointed out in the comments. I slipped a digit.
To recall, there have been recent allegations that having a dog does as much damage as driving a large SUV, on account of the carnivorous habits of the dog. Now there’s some question as to how much of the damage due to meat should be attributed to the dog, but even given a proportionate impact by weight, I found at a rough cut that supporting the dog was the equivalent of driving the SUV no more than 5 miles per day. [more]