I read the punchline first, too, though I can't remember quite why I did. If I hadn't, the conversation about burying him before the kids got up would have been quite interesting and morbid! It's a sad story which is probably why it took me so long to read it!
Here are my notes:
"it's all I can do not to cry" - Having read the end, this read wrong to me because dogs don't cry tears - they howl and whine. I just think there might be a better word than 'cry' that would fit for a dog but not give anything away.
"there are ways to punish bad behaviour without violence, and these are much more effective" - what ways?