Animals Turn to Nature for Self-Medication
It's not uncommon for humans who just visited the doctor to want to seek out a second opinion, some of them turning to self-medication for the answer. But now new research shows that this may apply to animals like dogs, elephants and chimps as well, who seek out drugs on their own to relieve certain ailments.
Scientists still aren't sure if this theory, known as zoopharmacognosy, is correct, but believers in the practice are convinced that humans can learn a thing or two from these animals - specifically, in terms of finding new medications.
"Much of folk medicine, particularly in the undeveloped world, likely came from medicine men watching animals self-medicate," lead author Joel Shurkin wrote in the journal PNAS.
Mother Nature's Pharmacy
Many animal species, from birds, bees and lizards to elephants and chimpanzees, have turned to nature as their own personal kind of pharmacy. They self-medicate using the environment's own ingredients to prevent disease, kill parasites, bacteria and viruses, or to simply aid in digestion.
For instance, seeing a dog munch on grass is nothing you haven't seen before, and an owner's first instinct may be to snatch away these greens to prevent their dog from getting sick. But according to Shurkin, that's exactly the point. Supposedly domestic dogs, and even cats, seek out the plant in order to relieve a stomach ache and expel whatever it is that's bothering them.
"Dogs do not have the means to digest grass, as they lack the enzymes needed to break down the fibers," Vancouver-based vet Dr. Michael Goldberg explained in the magazine Modern Dog. "Thus, there is little nutritional value in it for them. One reason for eating grass may be due to a feeling of nausea."
Elsewhere, chimpanzees have been observed swallowing leaves whole, using their rough sandpaper-like texture to remove parasites. More than 200 species of birds have also been seen rubbing themselves with ants to kill feather lice, a behavior known as anting. Ants that spray formic acid can kill off feather lice and protect the birds from infection.
Additionally, female capuchins have been known to rub sugary syrups on wounds, while North American brown bears treat insect bites using a paste of Osha roots and saliva.
But perhaps most astonishing are reports from back in October 2013, the Daily Mail notes, of mountain goats scaling a brick wall in the Gran Paradiso National Park in Northern Italy. It is thought that the animals were partaking in mineral licks, which is the licking of stones for their nutritious salts and minerals when food supply is low.
Medicine vs. Food
But how do you tell the difference between self-medication and just plain bizarre behavior?
For example, researcher Holly Dublin while observing a group of elephants in Kenya spotted a pregnant female eating the plant boraginaceae, which was not part of her regular diet. The expectant mother ate the entire plant and then returned to her normal feeding routine, suggesting that she perhaps just had a momentary lapse in judgment.
However, four days later she gave birth. This same plant is used by women in the region to induce labor, and so Dublin believes the elephant wanted the same effect.
Though it's hard to say what the elephant's motives were, Shurkin says there is a four-step process for helping researchers distinguish between self-medication and just a hungry animal.
"First," he wrote, "the plant eaten cannot be a regular part of the animal's diet; it is used as medicine not food. Second, the plant must provide little or no nutritional value to the animal. Third, the plant must be consumed during those times of year - for example, the rainy season - when parasites are most likely to cause infections. Fourth, other animals in the group don't participate."
If the animal's activity meets all this criteria, Shurkin says, then it demonstrates its ingenious ability to treat its own ailments.
"It's not clear how much knowing or learning is involved, but many animals seem to have evolved an innate ability to detect the therapeutic constituents in plants," the researcher wrote. "Although the evidence is entirely circumstantial, the examples are plentiful."
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