Mystery Solved: Icelandic Horses Probably Ate Cannabis

What was thought to be a rare nerve condition in some Icelandic horses has turned out to be the effects of having eaten cannabis, Vísir reports.

The story begins in 2011, when a group of horses in South Iceland were observed exhibiting strange symptoms. These included shaking, poor coordination, and a vastly increased appetite. The matter was brought to the attention of several veterinarians, none of whom were able to determine a cause, until the case arrived on the desk of veterinarian Mia Hellsten.

Mia told reporters that she happened upon the case by pure coincidence; the horses in question were not owned by any of her clients. At the time, she believed the horses might have been suffering from a new nervous condition. She opted to take the matter up with the American Association of Equine Practitioners (AAEP), an organisation of horse owners and carers.

She shared videos of the horses with experts at the AAEP, who all suggested any number of nervous conditions that could explain their strange behaviour.

“In the end, one person said the symptoms resembled that of a dog which has eaten someone’s cannabis cakes,” Mia says. “When the horses were tested, the results came back positive for cannabis use.”

The investigations went no further than this. It was suspected that the horses likely found cannabis plants growing outdoors and ate an unknown quantity of them—at least enough to have the effect that it did—and it is also unknown who was growing the plants in the first place.

The horses suffered no lasting damage from eating the plants, and have made a recovery.

“Those who examined this case did find it very strange,” Mia reflects in hindsight. “They had these symptoms, yet also had very healthy appetites.”