Am I putting my dog down too early?

I have a 15yo husky. Most posts Ive read where people ask this question, their dogs are limping, confused, etc. To me, that is something I dont want my dog to progress to ever. I rather be too early than a week late.

But at the same time, being early makes me uncomfortable. My dog certainly is slowing down. Sometimes not eating all day, getting stuck on the stairs so I have to push him up, overall low energy when he used to jump for joy during food time. However, he can still do a slow run if I run with him a short distance when I take him outside.

Any thoughts?