A California-based manufacturer has voluntarily recalled horse feed that could be contaminated with monensin.

Monensin is an ionophore antibiotic sometimes included in ruminant, swine, and poultry feed that is toxic to horses.

On Sept. 25, Western Milling LLC voluntarily recalled some batches of Western Blend horse feed after learning that several horses reported to have consumed the feed either became ill or died. A written statement from Western Milling indicates that the recall covers 50-pound bags, LOT 5251, manufactured by Western Milling on Sept. 8 and distributed to retailers in California and Arizona.

Of the 1,100 bags that were recalled, all but 67 bags have already been reclaimed by the company, the statement said