On Tuesday April 7, it goes to Tampa Bay Downs, a track which is available to international punters via UK bookies betting into the pools.
More details here - HANA
Note, it's about betting in a specific pool, not any race or any bet type. But don't just donate randomly, do the form for the race, and make use of the form links from the HANA site nearer the date.
Great cause and it does have meaning to people outside the US as well.