Cassandra Grant, 38, from Bristol, allegedly posed as a medic and accused of intravenously injecting an anti-sickness drug to a patient at the Blenheim Palace Horse Trials.
She has been charged with fraud by false representation and assault occasioning actual bodily harm.
She appeared at Oxford Magistrates’ Court on 29/9/2017.
She is due at Oxford Crown Court on 27 October 2017.