I had to make this decision this past May when I lost my Teddy. He was 14, suffering glaucoma (though managed well) and suddenly went into Kidney failure.
The Veterinarian saw my grief at the prospect of losing Teddy and suggested he could "go another 45-60 days on medication to manage his pain."
Teddy gave me so many good years, how could I be so selfish to make him go a few more days do avoid the inevitable? What kind of master would I be to him?! I couldn't do it. I had to love him enough to let him go.
At that point I made the necessary arrangements to do what was necessary. I took Teddy for a car ride, his favorite thing to do. He wouldn't even sit up to put his head out the window as he always did. He laid on the seat, nose up in the air as I had the windows down for him, and took in his last ride. I cried the entire time, me a (then) 55 year old man saying goodbye to his best friend.
We stopped to get something to eat together, and then I took him back to the Vet to ease his pain.
I laid there with him as the Vet put in the first, then second drugs that would send Teddy to the Rainbow Bridge. Once it was over, I spent some time with him continuing to pet him and tell him how much I loved him and would miss him.
His bed is still where it was that day. His ashes are on my fireplace mantle along with his picture, collar and leash. I miss him every day.
They're FAMILY. Unfortunately, we outlive them and we're the ones who have to make the decision for them. God gave us dominion over all the earth and with that comes the very responsibility we have for our canine companions.
That's how I see it and I hope this helps you.
Well said but I think it will be beyond the comprehension of the OP. Some people get it and some don’t.
They make fun of people who humanize dogs, cats, horses, birds, etc. They have no idea what they are missing.
That bond is like no other. It’s different than a human to human bond but just as real and just as strong as you clearly understand.