Five more horses were euthanized at Los Alamitos Race Course in Cypress after they tested positive for a potentially fatal infectious disease, the California Horse Racing Board announced Wednesday.

A total of 12 horses at the track have now been euthanized due to the outbreak of Equine Infectious Anemia.

Bullet Train V, a 2-year-old colt with two career races, was euthanized Sept. 24 after he was found to have EIA. Biosecurity measures were put in place at the track, and the California Department of Food and Agriculture began overseeing the situation.

Six more horses were subsequently euthanized with EIA:

— Opt In, a 3-year-old gelding with eight career races

— El Vencedor V, a 2-year-old gelding with four career races

— Amore For A Reason, a 3-year-old filly with eight career races

— Goodtyme, a 3-year-old gelding with nine career races

— Assaultt, a 2-year-old colt with five career races

— The Marksman V, a 3-year-old gelding with 10 career races

All 12 horses euthanized at Los Alamitos due to EIA were trained by Heath Taylor, according to the CHRB. The Daily Racing Form reported that Taylor also trained six horses who were euthanized with EIA in Texas.

After EIA was detected in Taylor horses in other states, the CDFA and U.S. Department of Agriculture began efforts to trace the disease, prompting testing of all of Taylor’s horses at Los Alamitos. That testing found two horses that were positive, and both were among the most recent five that were euthanized.