Adopting a Senior Dog?

Hello!

Tomorrow, I go to pick up my dog from the shelter. Today, I just happened to look at their listing they had for him, and it said he is 16 years old!! Now, I know that is just a guesstimation based on certain factors, but could they be way off? He certainly does not look it or act like it.

Basically - is it common for the estimated age to be wrong? I’m concerned I won’t have much time left with him. 😞