Thank you to Kam for this...... 

 WHY DOGS DON'T LIVE AS LONG AS PEOPLE
      (Author unknown)

Being a veterinarian, I had been called to examine a ten-year-old Irish
Wolfhound named Belker. The dog's owner, his wife, and their little boy
were all very attached to Belker and they were hoping for a miracle. I
examined Belker and found he was dying of cancer. I told the family
there were no miracles left for Belker, and offered to perform the
euthanasia procedure for the old dog in their home.

As we made arrangements, the owners told me they thought it would be
good for the four-year-old boy to observe the procedure. They felt he
could learn something from the experience.

The next day, I felt the familiar catch in my throat as Belker's family
surrounded him. The little boy seemed so calm, petting the old dog for
the last time, that I wondered if he understood what was going on.

Within a few minutes, Belker slipped peacefully away. The little boy
seemed to accept Belker's transition without any difficulty or
confusion.

We sat together for a while after Belker's death, wondering aloud about
the sad fact that animal lives are shorter than human lives. The little
boy, who had been listening quietly, piped up, "I know why."

Startled, we all turned to him. What came out of his mouth next stunned
me. I'd never heard a more comforting explanation.

He said, "Everybody is born so that they can learn how to live a good
life like loving everybody and being nice, right? Well, animals already
know how to do that, so they don't have to stay as long."