The United States Trotting Association (USTA), citing differences in breeds, said Sept. 26 it has ended its membership in the Racing Medication and Testing Consortium (RMTC) and rejected the proposed national model rules on uniform medication standards.

The USTA Executive Committee said it voted unanimously to leave the RMTC and reject the model rules pushed by the Association of Racing Commissioners International (RCI). The organization said it has contributed more than $1 million to the RMTC the past 10 years.

The USTA, based in Columbus, Ohio, in a release said it will ask RCI to maintain the current medication policies in effect for Standardbred racing.

RMTC chairman Alex Waldrop, president of the National Thoroughbred Racing Association, couldn’t be immediately reached for comment