My best friends have been an animal. Their loyality is undieing, and their always happy to see you. Even when they are not feeling good. Hearing about your best friend has be heart wrenching. Do what you feel is best for him and have no reqrets.
My Girlfriend and I have two cats, Lucifer, just turned 20 on New Years, and Ellie, going on 18. We both know that they both have lived a good life, but knowing that someday soon, one or the other will pass on. I will dread the day it happens. Until then, I will cheerish every moment they are with us. Even when they chose to wake us up at 3 am.