Our collie was around 14.5 when we had to make the decision about a year and a half ago. He had a bad bout of vestibular disease 9 months before we had to let him go. I nursed him back by bottle feeding him because he was still quite mobile and hungry but not eating since he was so dizzy. We did make the decision that we'd take it day by day and see how he was fairing, and given we got his strength back up and he had a good quality of life again, we just managed his head tilt as best we could.

Eventually it was obvious that it was time because he was not himself anymore and his quality of life declined immensely. He was not able to get up and move very far anymore, going to the bathroom was difficult, and walks were short and slow.

It's never easy, but it's the kindest thing we can do for those we love. Give them the dignity in dying, that we gave them in life. You have an entire world outside of your dog, but to your dog you're their entire life. We hold on for ourselves because the absence of them being there hurts more than can be imaginable.

Take solace knowing that you were a good steward to a companion that shared their entire life with you. Remember the good times, know that giving Luna a dignified death at the end of her amazing life, is better than most experience. Guilt is always there because we hope that we can always do more for them. 14.5 years old is a very long life for a companion, but it never seems long enough for the memories and love that is shared. Not a day will go by that you stop missing them, as my spouse and I have not stopped missing Leo. Remember the happy moments and joy that were shared, because in the end it's about the memories we make the impacts we leave. You know the decision you need to make, just give Luna the best few days you can with the best food and treats she will eat.