Billy Caldwell, a 12-year-old U.K. boy with epilepsy, has had his first seizure in months last night, his mother reports. The seizure comes just hours after U.K. border officials confiscated Billy’s medicinal cannabis oil at Heathrow Airport yesterday. The main active ingredient of the cannabis oil medication that Billy uses is CBD. But it also has enough THC to make it a Schedule 1 controlled substance in the U.K.

Billy’s mother Charlotte Caldwell had taken him to Canada to secure the medical cannabis treatment. Without it, Billy can have up to 100 seizures per day. Charlotte posted a video of Billy’s early morning seizure to the Facebook group Keep Billy Alive. A spokesperson for the Caldwell family told The Independent that Billy’s condition had been well controlled with cannabis oil.

“The last time he had a seizure was several months ago, and even then it was because he wasn’t well anyway and had a bug at the time,” the spokesperson said.

Billy began treating his epilepsy with medicinal cannabis in the U.S. in 2016. Last year he became the first patient in the U.K. to receive a prescription for cannabis oil from the National Health Service. Once he began using the medicine, he went nearly a year without a seizure.

However, last month the British government ended those prescriptions. So, with just one dose of Billy’s medicine left, he and Charlotte flew to Canada for help. Once there, The Hospital for Sick Children replenished their supply of cannabis oil.

But when Charlotte declared it to border officials at Heathrow Airport upon returning to the U.K., they seized the medication. She was defiant in a statement to the press after the confiscation.

“I will just go back

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