I’ve been working on a project for over a year now investigating the belief use of vultures and vulture parts in various sub-Saharan African cultures. One area of this belief use is for medicine – curing physical and mental illnesses. When I talk about my work, I often get an initial look of disbelief and then disgust. The “what are they thinking? Blech!” look. Most people are usually too polite to actually say anything beyond mentioning that they thought only Chinese Traditional Medicine used animals or animal parts, or share their thoughts about the illegal slaughter of rhinos and tigers. I used to react that way too. But, as I remind them and myself, our modern Western medicine also uses zootherapeutics, the practice of incorporating animal materials into medical diagnostics or treatments.
It is important to think about our own use of animals and animal parts in Western medicine, even as I look into other forms of medicine. My ideas about what is good or even rational in terms of medical treatment are grounded in my personal experiences with Western healthcare, my scientific knowledge and training, and my ethical views on species conservation, environmental stewardship, and responsibilities towards other living beings on this planet. Finding a position to observe and assess as objectively as possible is not easy.
But why do so? Because ethnomedicinal systems are part and parcel of cultural worldviews. Worldviews are notoriously difficult to change, and even a minimal change requires understanding. Secondly, dismissing knowledge because it doesn’t fit my worldview is equally wrong. I don’t know everything, so it is worthwhile listening to others to see what I can learn – and not only about the topic of discussion. Finally, it is possible that some claims are valid. I do not advocate biopiracy or species extinction. However, working with a community to identify the active medical compound produced by an organism, figuring out how to synthesize the compound for mass production, and compensating the community fairly for their knowledge is a worthy goal.
Zootherapies are not unique to non-Western healthcare systems. Many of the treatments and diagnostics we use in the West come from animals. My list below is neither exhaustive, nor meant to be any sort of recommendation. They are is just some of the many interesting cases of animal-based medicines used in Western healthcare. Anyone taking any medication should do their research and speak with a trained medical practitioner to assess if the risks and side effects are acceptable for their personal situation.
Insulin, a life-saving medication for millions of diabetics worldwide, was first given in 1922 to a hospitalized teenager in Toronto, Canada. This particular injection of insulin came from an ox pancreas. Improvements helped refine this animal-sourced insulin harvested from cattle or pig pancreas for wider use by people with diabetes (both Type I and Type II). Synthetic forms of insulin have been readily available since 1982 for those who may have religious or other ethical objections to insulin coming from cattle or pigs. The majority of insulin used today is a biosynthetic recombinant “human” insulin or one of its analogues, although animal-sourced insulin remains available.
Premarin is a conjugated estrogen made from the urine of pregnant mares. It is prescribed to women as hormone therapy replacement (HTR) to lessen symptoms of menopause like severe hot flashes. Boosting estrogen levels in women post-menopause also reduces risks of osteoporosis, heart disease, and stroke. Some women object to taking Premarin because of the industrial production process where the horses are kept in a constant state of pregnancy to produce the estrogen-laden urine. Synthetic estrogen HTRs are available.

As a kid, finding a leech on my legs or between my toes after wading in the creek behind my house was pretty gross. You might think that leeching someone went out with the Middle Ages, but hirudotherapy is still used by Western healthcare specialists. Research shows that leeches produce more than 20 active compounds in order to feed. These compounds have analgesic, anti-inflammatory, antimicrobial and anticoagulant properties among other things. Doctors may use leech therapy to increase blood circulation or break up blood clots during plastic surgery or to prevent diabetic limb amputation. Chemicals found in leech saliva have been used to make drugs for hypertension, varicose veins, hemorrhoids, skin problems, and arthritis. Additional uses for osteoarthritis and cancer are also being explored.
“The rabbit died” used to be a phrase that either brought great joy or anxiety/stress, but it was a misnomer. Throughout history people have come up with various tests to determine if a woman was pregnant. In 1931, two researchers at the University of Pennsylvania, Lapham and Friedman, figured out that if you injected an immature female rabbit with a woman’s urine you could determine if the woman was pregnant. The hormone human chorionic gonadotropin (HCG) is found at high levels in a pregnant woman’s blood and urine. HCG causes the ovaries of an immature rabbit to mature rapidly. To test for pregnancy, a young rabbit would be injected with urine and then dissected a few days after the injection to see if the ovaries matured. So the rabbit died whether or not the woman was pregnant. Mice could be used in a similar way. Around the same time, a less invasive bioassay using Xenopus laevis frogs was developed by South African scientists. Female Xenopus injected with urine having high levels of HGC will produce eggs, so there is no need to kill the frog. More tests over the years have been done with frogs than rabbits, but the original phrasing stuck. The modern home pregnancy stick test, no animals required, was patented in 1968 and reached US markets in 1977. Concerns about sexual morality and women being able to perform the test and cope with results on their own led to this delay.
My mom never drank orange juice with breakfast if she could avoid it. My grandma soured her on it by making her drink a spoonful of cod liver oil mixed into her orange juice every morning as a kid. The name gives away the source of this oil – cod livers. It is high in Vitamins A and D, as well as Omega-3. Researchers are looking into other potential uses including reducing inflammation and heart disease risk, improving bone health and symptoms of rheumatoid arthritis, and supporting healthy eyes. The big problem is that overfishing of cod fisheries make them vulnerable to collapse – seen most recently in the North Atlantic. You can still buy cod liver oil but I don’t recommend fish-flavored orange juice (of course I tried it).

Prevagen is recommended as an over-the-counter supplement to improve brain function and sharpen memory. The listed active ingredient is a protein, apoaequorin, found in a jellyfish species (Aequorea victoria). Scientists at the Center for Science in the Public Interest have written about the flunked science trials of this supplement and legal case between the US federal government and Quincy BioScience, Prevagen’s manufacturer, as has the American Council for Science and Health. However, an aging population and stressful culture have kept sales high over the past decade. Given that it is a jellyfish – no spinal cord, no cute face or behavior, although it is bioluminescent – there isn’t much outcry from animal rights advocates either. Research on the active ingredient’s effects on brain function continue though as people seek a remedy for memory loss in old age.
There are a great many other animal-sourced medicines, treatments, and supplements used in Western healthcare. Chondroitin from shark and cattle cartilage, snake venom, vaccine serums (this is why you’re asked if you are allergic to eggs), etc. What’s piques your interest?
References:
- American Journal of Ethnomedicine. Webpage defines a number of concepts associated with ethnomedicine and zootherapies.
- Costa-Neto, E. M. (2005). Animal-based medicines: biological prospection and the sustainable use of zootherapeutic resources. Anais da Academia Brasileira de ciências, 77(1), 33-43. [paper is in English]
- Healthline (2019) What is leech therapy? Accessed 6/13/19.
- Pachamama Alliance (2019) Bioprospecting and biopiracy. Accessed 6/13/19.
- Pershing, A. J., Alexander, M. A., Hernandez, C. M., Kerr, L. A., Le Bris, A., Mills, K. E., … & Sherwood, G. D. (2015). Slow adaptation in the face of rapid warming leads to collapse of the Gulf of Maine cod fishery. Science, 350(6262), 809-812.
- Queensland Health (2019). Medicines/pharmaceuticals of Animal Origin. Queensland Health Guidelines, Doc #QH-GDL-954:2013.
- Schardt, D (2017). Prevagen: how can this memory supplement flunk its one trial and still be advertised as effective? Center for Science in the Public Interest, 11/20/17.
- Schwarcz, J (2019). Prevagen for mental clarity? American Council on Science and Health, 1/24/19.
- Sig, A. K., Guney, M., Guclu, A. U., & Ozmen, E. (2017). Medicinal leech therapy—an overall perspective. Integrative Medicine Research, 6(4), 337-343.
- Yong, E. (2017) How a frog became the first mainstream pregnancy test. The Atlantic, 5/4/17.