Previously you could go by the rule of thumb that one dog year is equivalent to seven human years. That is no longer valid. New charts take into consideration the size of the dog. Big dogs just do not live as long as small yippy dogs. That should be reversed. Sorry I am not a fan of small dogs.
Leann used this chart to determine that Sammy turned 100 years old in early September. Happy birthday old man. I hope I am still hiking like you when I reach the century mark.
HAPPY TRAILS, STEVE