Land O’Lakes Purina Feed, LLC has initiated a voluntary recall of specific sweet feed for horses at a Turlock mill location after a banned medication, zilpaterol, was found in 48 horses earlier this year.

Zilpaterol is a feed supplement given to cattle to increase their size, feed efficiency, and value. Its properties are close to those found in athletes using anabolic steroids, and is banned in thoroughbred races.

Zilpaterol is listed as a Class 3 medication, and its use remains a severe penalty for horse racers by the Association of Racing Commissioners.

On Tuesday, the racing board announced that 48 positives sources of zilpaterol have been found in runners at every track in California. The racing board believes that traces of zilpaterol have been distributed from Turlock’s feed supply since February.

It wasn’t until March 1, after taking a sample from a race horse, that the board had realized what had been added to their feed. They have found traces of zilpaterol in Purina’s Race Ready, Purina Strategy, Purina Omoline-200, Country Acres Horse Feed, and Country Acres Sweet-12.

“Given these test results, and as a precautionary measure, we recommend that race horse owners discontinue using Purina horse sweet feed products under the brands Purina or Country Acres that were manufactured at the Purina Turlock plant,” stated a press release from Purina’s Animal Nutrition.

“As soon as tests confirm feed manufactured at Turlock is free of zilpaterol, we will make that product available. We continue to work in partnership with the CHRB and will continue to provide updates as information is available.”

Zilpaterol is known to have a negative influence on horses’ health, but no reports of illness have been made in connection with the feed.

 “We have had no reports of any horse health issues, nor would we expect any, related to these low levels of zilpaterol. Purina Animal Nutrition does not use zilpaterol at the Turlock facility or at any Purina plant,” said Rebecca Lentz of Land O’ Lakes corporate communications.

All cases of chemical enhancement brought to the California Horse Racing Board from March 1 to March 26 will also be dismissed. The board suspects that the small portion of zilpaterol found in the horses’ system should be eliminated by the beginning of April.

Purina is conducting a series of investigations in the Turlock plant to discover why the feed was only affected within this general area.

“At this time, our investigation has led us to look closely at a single ingredient from a single supplier, impacting the Turlock facility only,” said Lentz.

No further comments were made towards the investigation, or where the ‘single supplier’ may be located.