By: Steve Anderson

Two horses that qualified for six-figure Quarter Horse Derbys to be run at Los Alamitos this weekend will not start after testing positive for banned medications in recent track-sponsored out-of-competition tests, the track announced in a statement on Thursday.

Trippys Royal Jess was the fastest qualifier for Saturday’s La Primera Del Ano Derby but will not run after testing positive for zilpaterol, a muscle builder. Trainer Christopher O’Dell said in an interview on Thursday that Trippys Royal Jess tested negative for the banned medication in post-race urine and blood tests conducted by the California Horse Racing Board.

O’Dell said a second hair follicle test will be conducted.

Whata Corona will not start in Sunday’s El Primero Del Ano Derby after testing positive for clenbuterol in a hair follicle test, the track said. Trained by Paul Jones, Whata Corona was second in a division of the El Primero Del Ano Derby trials on March 12.

The hair follicle tests were conducted on March 15. For the last two years, Los Alamitos has conducted out-of-competition testing on qualifiers of major stakes for such medications.