By: BloodHorse Staff

CHRB Issues Jimson Weed Warning

Photo: Courtesy California Horse Racing Board

Images of jimson weed, which is toxic to horses


The California Horse Racing Board issued a warning Nov. 14 to horsemen at Del Mar to be diligent for possible jimson weed contamination in bedding straw.

While only one contaminated bale has been seen so far, the CHRB is showing “an abundance of caution” by sending out a warning to horsemen, according to CHRB medical director Dr. Rick Arthur.

“It is certainly not a crisis, but this weed can contain scopolamine, which is a prohibited substance,” Arthur said. “Now, the likelihood under our current procedures of getting a positive from environmental contamination is rather low. It is simply good husbandry to take the weeds out of straw, and we don’t want to not say anything and have someone come up with a positive that is totally avoidable.”

Jimson weed also naturally produces the alkaloid atropine, which can function as a bronchodilator and is also a banned substance. In general, the weed is poisonous to horses. Arthur said, however, well-fed horses would be unlikely to choose to eat this bitter-tasting weed.

The straw was brought onto the backside as part of a delivery to a single trainer. Jimson weed tends to overgrow in drought conditions so all trainers are being reminded to inspect their straw deliveries, Arthur said.

Del Mar opened its fall meet Nov. 11 and will be running through Dec. 4.