The final Waterloo Cup hare coursing event began at Altcar, Merseyside, on Monday.
About 200 demonstrators marched to the event many carrying banners and placards.
Coursing enthusiasts were kept back by mounted police as they heckled protesters.
Spectators threw mud and other missiles at anti-blood sports protesters.
More than 50 officers policed the protest, at least two pro-hunt spectators were arrested.
The final Waterloo Cup is expected to attract more than 10,000 supporters over its three days.
The event dates back to 1836 and once attracted crowds of 75,000.