The parable is meant to be cute, of course. We don't know what moves an animal's mind; if they have a position at all, I'd say cats are atheists. But the preacher is on to something here.
Among humans, a blessing can bounce either way: you either find yourself lucky, and feel grateful and indebted, or you call yourself entitled, and ignore or resent others. The dog says, "Let me herd your sheep, guard your house, sniff your bombs, pull your sled, fetch your duck. For your dog biscuit has so indebted me that I can never pay it down." Meanwhile, the cat won't even come when you call it.
And that second bounce is fallacious; the self-made man is impossible. We all swirl in an infinite exchange that makes all "deserving" a non sequitur. We may argue that one payoff has more merit than another, but ten thousand kalpas of deals were cut before those coins were even struck. An honest audit must seive the entire account, every transaction, hand to hand, second by second, to the beginning of time. Thus the Quotient of Being: "I owe, therefore I am."
Yet wealth, whether money or love, suppresses this fact. That's why the wealthy – the rich man, the pretty woman, the young, the healthy, the cherished, the well-fed – are so ungrateful. And that's why Jesus and Gautama both urged poverty, material and emotional, on their disciples.
At home, in comfort and plenty, I can slurp down a whole cup of tea and not even remember. In the woods, all my gratitude could not balance the bliss of just one sip.
(Adapted from 100 Days on the Mountain, copyright RK Henderson.)