When you’re walking your dog, have you ever noticed that they will go sniff a plant and then promptly try to eat it? Obviously, our first reaction is to tug them away from the plant because who knows if that random plant on the side of the street is poisonous or not. However, this might be a sign that your dog is trying to heal itself. Animal self-healing is known as zoopharmacognosy and a number of animals other than dogs like birds, bees, lizards, elephants, and chimpanzees can do it.

Table of Contents:

• Zoopharmacognosy from Ancient to Modern Times
• More Examples!
• What Can We Learn from It?

Zoopharmacognosy from Ancient to Modern Times

         Zoopharmacognosy is not a newly discovered phenomenon. In fact, Aristotle, Pliny, Aelian and other naturalists have all documented it. Aristotle observed dogs eating grass to purge parasites and bears consuming wild garlic for post-hibernation nutrients. Similarly, Pliny noted deer eating wild artichokes to detoxify and seeking crab shells (rich in immune-boosting chitosan) to counteract spider venom. Aelian recorded elephants treating wounds with olive flowers and birds like storks using oregano as an antiseptic poultice.

         Even now, animals still use medicinal substances to treat ailments. Birds like finches incorporate nicotine-laden cigarette butts into nests to repel parasites, while veterinarians apply the concept by letting dogs and horses select healing herbs through scent. These accounts not only reveal animal self-medication but they also show how their actions have influenced traditional human medicine.

More Examples!

• Chimpanzees swallow rough Aspilia leaves whole to purge intestinal parasites, a behavior observed by primatologists like Huffman and Wrangham.
• Bonobos carefully fold toxic Manniophyton fulvum leaves on their tongues to avoid irritation while using them to combat parasites.
• Monarch butterflies infected with parasites lay eggs on toxic milkweed, which their caterpillars eat to reduce infections.
• Swallows use toxic celandine as a poultice for chicks’ eyes and turmeric (anti-inflammatory) for healing, per 14th-century manuscripts.
• Weasels roll in toxic rue to treat wounds and snakebites, a remedy noted in folk medicine.
• Snakes rub their eyes on fennel after hibernation to promote tissue repair.
• Wild goats chew sphagnum moss (antibacterial) for wounds, just as Sumatran orangutans use liana vines.
• Bears coat wounds with mullein (anti-inflammatory), documented in the 12th-century Aberdeen Bestiary.
• Deer eat wild artichokes to detoxify and seek crab shells (rich in immune-boosting chitosan) to counteract venom.

What Can We Learn from Zoopharmacognosy?

         Over millions of years, species have honed the ability to detect and use natural remedies for survival. Humans, too, likely inherited early medical knowledge by observing animals—from Indigenous healers studying local wildlife to medieval scholars documenting bear and swallow remedies.

         Today, this ancient wisdom holds untapped potential. Just as ethnobotany has led to modern drugs (e.g., aspirin from willow bark), rigorously testing zoopharmacognosy claims could unlock new therapies. By bridging animal instinct with scientific inquiry, we not only trace the roots of our own healing traditions but also open a living library of evolutionary medicine, where nature’s oldest doctors guide future discovery.