NRML, I'm not going to post the whole thing on here, but there exists a verse that teaches you very nicely how to tell the age of a horse. The second verse goes like this: The dark cups nearly dissapear from the middle two in just one year,
In Two years, from the second pair; in 3 the corners too are bare.
At 2 the middle nippers nippers drop; at 3 the second pair can't stop.
When 4 years old the third pair goes; at 5 a full ne set he shows. The deep black spots willl pass from view; at 6 years form the middle two.
It was written by OR Gleason and modified by Dale Jeffrey.