"I'm really sad..."

So just a few minutes ago I caught Elijah outside grabbing dog food out of the dog's bowl and throwing it at them in the backyard. We have been over this a FEW times in the past, and he knows he is NOT supposed to touch the dog food (for a long while we had trouble with him eating it, and it would upset his tummy). So, I went out there, made him come over to me, and I told him to stop that because he was making a mess, and wasting food. He said, "The doggies are hungry, Mommy!" So I told him that they would eat when they're hungry, and that he's NOT supposed to touch the doggies food. So, I went back inside, and a second or two later, I heard him laughing. I peaked out the window, and sure enough, he was grabbing what he had previously thrown on the ground, and was throwing it back towards the dog bowl (of course, it was flying everywhere). So, I went outside, and called him back over to me, and spanked his bottom twice. Then re-explained why I didn't want him touching the dog food, and that he got a spanken for not listening. So, he said sorry, and I went inside. This time I stood there for a second, and he looked at the dogs and said, "Are you hungry girls?" He sat down next to them, and said, "I'm really sad... I'm very sad... I better go lay down and take a nap." And then proceeded to go lay down on the concrete!! Broke my heart! (Of course that lasted less than a minute, and now he's up running around and playing again!)