nuetering and age?

[AVA]

I once had a person tell me my dog was too old to be nuetered,
this was about a year ago at a social gathering at the dog park. Can't remember exactly the conversation or who this person was but its been stuck in my head ever since. For all I know it could have just been one of those "type" of people who think they are an expert.
My dog is 13 and he is still intact. My personal reason for not getting him nuetered is first off, he has a respiratory health issue that would make his chance of surving anethesia very bad odds plus that fact that his breed is highly intolerant to some anethesis. I've had him since he was only a couple years old and seeing how he is never allowed to roam free except at the dog park under my supervision
and I am a very responsible pet owner. No pound puppies here.
Does anybody think that statement could be true? that a dog could be too old to nueter? I'm just curious and hoping to get it out of my head I guess. Never did ask my vet that question, didn't want to bring up the subject of nuetering so that he might try to convince me to get him nuetered, thats just not gonna happen, he would never survive.