I watched this movie the other day as I like to have the TV on while writing. I made me think: our dog's life is just a tenth of our existence; while our life is the entire existence to our dogs. It made me both sad and inspired to make my dog's life the best fucking experience she'll ever have.
Yes, the very feeling that your dog will not live as long as you live is scary. I have a cat and I get the same feeling. But this is how nature works.