A newborn foals legs are already 80 to 90% of the length they will be when full grown.
Horses like classical music.
The oldest horse was named Old Billy. He was a cross breed, he was born in 1760 and lived to 62.
The oldest pony ever recorded was named Teddy E. Bear. He lived to be 55 and was owned by Kathy Pennington of Virginia Beach, VA. He was still alive in 1998.
The World's Largest Horse was a purebred Belgian stallion named Brooklyn Supreme. He stood 19.2hh (6'6") at his withers. He weighed over 3,200 pounds and is entered in the Guiness Book of World Records. He was foaled in 1928 and died in 1948. He lived in Iowa, USA. (I'm not sure about this one as the stats are always changing and no one can seem to find out who the REAL tallest horse is)
Oldest winning thoroughbred racehorses:
The 18-year-olds - Revenge, at Shrewsbury, England 1790; Marksman, at Ashford, Kent, England, 1826; and Jorrocks, at Bathurst, Australia, 1851.
Also at 18yrs old; Wild Aster won three hurdle races in 1919, and Sonny Somers won two steeplechases in February 1980.
This horse was a Thoroughbred born in Chile, and originally called "Faithful". He was a racehorse and retired from racing in 1944 to begin training in the Chilean Cavalry School. There he was taught dressage and jumping. His training was overseen by Chilean Cavalry Officer Major RAFAEL MONTTI, who was in charge of several other horses at the time and hoped to train one that could beat the current world record, set by Captain Antonio Gutierrez of the Italian Cavalry on an Irish horse named Osoppo.
After setting the record, (he was 16 years old when he jumped) Huaso was retired and never ridden again. He died of natural causes at the ripe age of 29.
Vid made from stills: http://www.ultimatehorsesite.com/images_info/worldrecordjump.gif
The only US army survivor of Custer's last stand was a horse named Comanche. Contrary to popular belief he was not Custer's horse. He was found on the battle field and had many arrow wounds. He fully recovered and was retired from service, only brought out for parades and that sort of thing. He lived to the ripe old age of 29.