Anyone who has ever tried growing cannabis outdoors will be aware of the need to protect plants against common pests like aphids and other bugs, yet the truth is that it isn’t just creepy crawlies and microbes that you need to watch out for. A number of larger wild animals, from mice to horses, have been known to eat cannabis plants, and have occasionally been seen looking a little stoned after gorging on some poor grower’s stash.
Which Animals Eat Cannabis?
The number of species that eat cannabis in the wild isn’t fully known, although reports suggest that a wide array of animals like to nibble on the various parts of the plant. Many types of bird, for example, are regularly seen consuming cannabis seeds, which can be a major problem for breeders who need to bank or sow this vital genetic material.
Species such as ringtail pheasant, bobwhite quail and mourning doves all consume hemp seeds as a major constituent of their diet, while it has been reported that captive doves can be kept in good health by feeding them nothing but cannabis seeds.
For most casual growers, however, the threat from the air is pretty much negligible, and it’s the four-legged creatures that need to be guarded against. Many mammals are known to eat cannabis plants when given the opportunity, with mice and rats being particularly problematic diners.
In one notorious instance, cannabis growers in Hawaii began to suspect mongooses of raiding their fields after noticing the presence of seeds in their droppings. However, closer investigation revealed that these mongooses were in fact preying on mice and rats that had become accustomed to gorging themselves on weed and ending up too stoned to evade predators.
Horses and mules have been observed eating cannabis flowers in Greece, while a veterinary report from the 1950s describes a Greek lamb that repeatedly binged on bud, yet grew and developed normally, with no unwanted health effects.
Deer, meanwhile, are known to avoid plants with strong aromas, but have been known to eat cannabis from time to time. Numerous reports suggests that monkeys also tend to feed on the plants in South America, while Kenyan farmers claim that a type of antelope known as a dik-dik also has a taste for marijuana[i].
What Happens When Animals Eat Cannabis?
Animals that eat cannabis seeds, stems and leaves are unlikely to experience many effects, although those that munch on the flowers do occasionally get high. For instance, one Canadian mouse made global headlines in 2020 when it was found to have passed out after bingeing on a home-grower’s plants.
An interesting early study that was carried out in India back in the 19th century investigated the effect of giving cannabis resin to various animals, providing some intriguing – if ethically dubious – findings. For instance, the study authors wrote that “while carnivorous animals and fish, dogs, cats, swine, vultures, crows, and adjutants, invariably exhibited the intoxicating influence of the drug, the graminivorous, such as the horse, deer, monkey, goat, sheep, and cow, experienced but trivial effects from any dose we administered.”[ii]
It’s likely that the scientists behind this study are the only people ever to have seen a stoned fish!
More recent research has indicated that lab mice become less aggressive after being administered cannabis, suggesting that wild mice may also exhibit behavioural changes when nibbling on weed[iii]. Clearly, then, humans are far from the only species that likes to ingest cannabis, although it’s certainly not a good idea to go around feeding marijuana to animals. Dogs, for example, metabolise cannabinoids much slower than we do, so it really is wise to try and keep your furry friend away from your stash.
[i] McPartland JM. Cannabis pests. Journal of the International Hemp Association. 1996 Dec;3(2):52-5. – http://druglibrary.org/olsen/hemp/IHA/iha03201.html
[ii] O’Shaughnessy WB. On the preparations of the Indian hemp, or Gunjah: Cannabis indica their effects on the animal system in health, and their utility in the treatment of tetanus and other convulsive diseases. Provincial Medical Journal and Retrospect of the Medical Sciences. 1843 Feb 4;5(123):363. – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2490264/pdf/provmedsurgj00865-0001.pdf
[iii] Santos M, Sampaio MR, Fernandes NS, Carlini EA. Effects of Cannabis sativa (marihuana) on the fighting behavior of mice. Psychopharmacologia. 1966 Nov 1;8(6):437-44. – https://link.springer.com/article/10.1007/BF00406492