It's been part of a hotly debated topic on the Waikato District Police Facebook page after officers posted an image of two cows chewing the special grass.
"Rather than hitting you with stats and "don't do drugs" comments, we thought we'd take a lighter approach and run a competition. Caption the photo below," they wrote, with the disclaimer: "We know cannabis can be toxic to animals and it was taken off the cows well before they could enjoy their high tea."
The post has gained over 1000 comments, with many caption suggestions but also discussions on cannabis law and consumption.
The most-liked caption came from David Ireland. "They were willing to risk it, but the steaks were high," he wrote.
Other top captions included:
- "Maybe the cow will jump over the moon now!!" (Duncan Bennett)
- "'Wasted' milk" (Nathan Fowler)
- "Jamaica becomes biggest buyer of New Zealand milk" (Barry Curtis)
- "420 graze it" (Dakota Davidson)
- "So this is why there's a green top milk" (Te Ahuora Mac)
- "Fonterra explain their high milk prices" (Rozanne de Wild)
- "Just weeding out the crimoonals" (Kellie Perry)
- "Cannibeef" (JP Taute)
Can cows even get stoned?
Evidence shows that yes, cattle can get high. However it seems they don't enjoy it, and high doses can be fatal.
In a 1998 article for Veterinary and human toxicology, scientist David Driemeier reported a case where five cattle ate 35kg of marijuana.
A farmer had mistaken 10 pressed barrels of dried marijuana leaves for hay, and threw it in the paddock where the cows were.
"Clinical signs started 20 [hours] after the ingestion and included intense muscle tremors, mydriasis, abundant salivation, reluctance to move, uncoordinated gait, and froth from the mouth," the report says.
"Deaths occurred 1 day (2 yearling calves), 2 days (1 yearling calf), and 2 days (1 adult cow) after the ingestion. The fifth animal (a mature draft castrated male) recovered without treatment."
He reports another 8 horses and 7 mules died after ingesting marijuana in Greece.
What happens when other animals eat marijuana?
In 2016, an infamous incident happened in Wales when a herd of sheep devoured a bunch of cannabis plants and wreaked havoc in a sleepy Welsh village.
Witnesses complained the sheep had roamed the village in a daze and were breaking into people's gardens. One was killed when it wandered in front of a car.
In 2015, the US National Public Radio programme reported a dramatic rise in pet poisoning from marijuana.
The Pet Poison Helpline had seen a fourfold increase in calls regarding pets intoxicated after eating cannabis.
The report came a month after a popular video on YouTube showing a man's dog looking very dazed, stumbling and having trouble blinking. "What's wrong with you, buddy?" the man says to his dog in the video. The man laughs, knowing the pooch had eaten a brownie, baked with marijuana in it.
Dogs and cats might be more susceptible to marijuana intoxication than humans, NPR reported.
"Every species metabolizes drugs differently," emergency veterinarian Dr. Stacy Meola told the broadcaster.
In his book Intoxication: The Universal Drive for Mind-Altering Substances, Ronald K. Siegel wrote: "After sampling the numbing nectar of certain orchids, bees drop to the ground in a temporary stupor, then weave back for more.
"Birds gorge themselves on inebriating berries, then fly with reckless abandon. Cats eagerly sniff aromatic "pleasure" plants, then play with imaginary objects.
"Cows that browse special range weeds will twitch, shake, and stumble back to the plants for more.
"Elephants purposely get drunk off fermented fruits. Snacks of "magic mushrooms" cause monkeys to sit with their heads in their hands in a posture reminiscent of Rodin's Thinker.