Vegan Beware: Animal Products used in Common Medical Tests

Hardcore vegans proudly proclaim they don't eat animals or animal products, don't use products tested on animals, and don't wear animal products. I wonder - are vegans also willing to do without diagnostic medical tests that use animal products? Before you say, "Of course!" make sure you know what you are giving up.

Way back when I was a medical technologist, we kept awake one graveyard shift by compiling a list of all the animals our lab tests depended on. Macbeth's witches didn't use as many different species as we did. Not much has changed since then. The tests use smaller samples, the equipment is faster, but the animal products are still in use.

Because it's been in the news recently, I'll start with heparin, which is made from pig intestines. Labs use heparin to prevent blood from clotting between collection time and analysis for a few blood tests. The most critical test is blood pH, (how acid or alkaline your blood is). If your pH is too far from normal, you die. None of the chemical anti-coagulants can be used for this test because they change the pH of the sample.

The bacteriology lab is where animal products are most evident. To identify which bacteria is causing an infection, the lab isolates and grows the bacteria, looking for distinctive growth characteristics. Some pathogenic bacteria, such as the ones that cause whooping cough, tuberculosis or diphtheria, are fastidious. They will not grow without animal products. To isolate them and diagnose an infection, the growing media must be supplemented with whatever the bacteria requires: eggs, meat chunks, gelatin, broths, blood serum, hydrolyzed proteins, extra amino acids or other animal products.

Immunology: Any test with "immuno" in the name uses antibodies produced by an animal or cells from an animal to detect the presence or measure the quantity of something. The ELISA or ELISA/EIA tests for HIV, pre-marital blood tests, prenatal TORCH (Toxoplasma, Other [syphilis], Rubella, Cytomegalovirus, Herpes) tests, blood tests to diagnose viral infections, and allergy tests done from blood samples instead of a scratch tests on the patient's skin are examples of immunology tests.

Transfusions are also "immunology" because the blood bank is looking for antibodies that might destroy red blood cells. Besides bovine serum albumin (purified protein from cow blood), the "Coomb's reagent" (rabbit, goat or mouse antibodies to human blood), pre-transfusion testing may require various animal-derived antibodies to the human blood groups. This is the only testing where human-derived products are used, in the form of red blood cells that have rare blood types.

The chemistry lab, which sounds as though it would be free of biological products, but it isn't. Many of the chemistry tests are measuring enzyme levels in the patient, using an immunological assay. Drug screening, heart attack diagnosis, and kidney function testing are among the tests that use animal products in immunoassays.

Moving on to hematology, where "coagulation" is tested, there are more animal products. If your blood doesn't clot fast enough, or if it's clotting too fast, you die. Anyone taking anticoagulant medications will be regularly tested to make sure the medication is doing what it should. This testing uses extracts of rabbit brain, and an enzyme from snake venom (Bothrops atrox, the fer-de-lance of South America).

Even home test kits can be animal-based. Find the pregnancy test section at a local drugstore, and look at the ingredients for the tests. The manufacturer's advertising may call it a "specially treated strip on a pregnancy test stick", but the "monoclonal mouse antibodies" they list on the contents are made by mice or cells from lab mice that have been immunized against HCG. Anti-mouse antibodies, usually made by goats, are also on the strip.

It's better than the old days, when "the rabbit died" was not slang for having the lab call with news of a positive pregnancy test. The rabbit really died! Before 1972, when the immunoassay test called the "Paper Rabbit" was introduced, pregnancy tests for humans used live animals: rabbits, mice, frogs or toads. Pregnancy testing was less common, took several days, and cost a lot more money. You injected the woman's urine into the animal, waited the required time, and then looked for changes to the ovaries in rabbits or mice (after killing them), or the production of eggs or sperm in the amphibians (they could be reused). Did we enjoy killing bunnies or mice? Of course not. And trying to get a toad to pee so you could check his urine for sperm was ... well, you had to be there to understand how icky it was.

So, vegans, now that you know that animal products are widely used in routine medical testing, which of these tests are you going to decline? Pregnancy tests? Transfusions? HIV testing? Drug overdose detection?