Veterinarians treating thoroughbred racehorses in NSW have reached agreement with the state's regulatory authority in a long-running battle over licensing.

From September 1, vets working in the metropolitan area will be regulated under a local racing rule and must have a Racing NSW permit.

The rule will be implemented for vets outside the city from December 1.

"The implementation of the rule will support Racing NSW in ensuring that Racing NSW is utilising the best practice integrity model," Racing NSW chief executive Peter V'landys said.

"Racing NSW is committed to the ongoing consultation with Equine Veterinarians Australia in informing and clarifying rules and protocols that will apply to veterinarians working with racing thoroughbreds."

V'landys said the input from Equine Veterinarians Australia president, Dr Ian Fulton, had been invaluable.

"We couldn't have reached this compromise without his leadership," he said.