["Earl will live at least another 50 years. ]

I think the lady in the article is confused on the life span of horses & ponies.
But they do live longer than dogs.

http://en.wikipedia.org/wiki/Miniature_horse
[They are generally quite hardy, often living longer on average than some full-sized horse breeds; the average life span of miniature horses is from 25 to 35 years.[5]]