How Mister Ed was laid to rest...
By the time Mister Ed reached the grand age of nineteen he was suffering from a broken leg and a variety of health problems. In 1970 he was quietly put to sleep with no publicity. The horse which died in Oklahoma in 1979 (who everyone thought was Mister Ed) was in fact just an animal that once posed as Ed for some publicity photos used by the production company.
http://en.wikipedia.org/wiki/Mr._Ed