James Thurber (I think. If not, it could have been William Saroyan. I sometimes get them mixed up.) wrote a wonderful essay on the passing of the old dog that his children had grown up with. I vaguely remember the piece ending with something along the lines that she looked up at him with big, understanding eyes "as if to say 'And this is as natural as chasing the rabbits or having the puppies or playing with a ball."   (The only words that are probably his are the "This is as natural as ... having the puppies ... ."   The others are approximations.)

I'd love to find that essay again.