"We shaved 19 days off our schedule to keep the purses at a higher level, but since then, the level has dropped again, so you either have to lose more days or you have to adjust your purse schedule. There's only two ways to go in and slice that," said Bessie Gruwell, executive director of the association.
Delaware Park shortened its racing season last year.
Delaware has casinos at three racetracks. In addition to Delaware Park, there are casinos at Dover Downs and Harrington Raceway.
Slot machine revenue for the three casinos was $637 million in 2006, when the first Pennsylvania casino opened. It has fallen every year since. Last year, Delaware slot machine revenue was $375 million, and it is down nearly 10 percent for the first six months of 2014.
Horse racing's slice of that revenue fell to $34 million last year from $72 million in 2006, according to data from the Delaware Lottery, which regulates casino gambling.
Conditions are not expected to improve with the scheduled opening of a casino in downtown Baltimore at the end of this month. Delaware lost significant gambling revenue when Maryland Live! opened in Hanover, Md., two years ago.
The money in the Mid-Atlantic region gets split into smaller and smaller slices, Gruwell said: "We're all trying to attract the same basic customers."