Australia retired after developing hoof problem

Aidan O’Brien has hailed Australia as "unique" following the announcement that the three-year-old has been retired to stand at Coolmore stud.

The Ballydoyle handler has made no secret of his regard for the colt, who represents the bluest of blood lines as a son of Derby winner Galileo out of Oaks victor Ouija Board.

O’Brien’s high opinion was justified as Australia claimed victories in the Epsom and Irish Derbys before going on to prove himself a top-class performer over 10 furlongs when winning the Juddmonte International at York.