National Anti-vivisection Society


National Antivisection Society

Animal experiments: the facts

. Updated: 24 February 2015


Every year millions of animals suffer and die in experiments that can never be trusted. It is claimed vivisection is essential to medical progress. However, our research indicates that not only are animal experiments misleading, they can actually hold up medical progress.


Founded in 1875, the National Anti-Vivisection Society (NAVS) is the world’s premier anti-vivisection group, campaigning tirelessly since its inception to expose the cruelty and futility of animal experiments.

We organise and fund educational films; undercover investigations of laboratories; detailed scientific reports for MPs, MEPs and the public.

Our Lord Dowding Fund awards grants towards scientific and medical research that does not involve animals.

Our campaigns have put an end to the requirement for A-level students to dissect animals in schools; enabled university students to refuse to use animals in their studies, and provided them with alternatives; helped to persuade governments and drug companies to abandon cruel safety tests such as LD50, cosmetics testing, and persuaded more and more companies to drop animal testing of their products.

Against a wall of secrecy and vested interests, we are succeeding in our campaigns against the needless suffering of laboratory animals; with your help we will win.

Animal experiments are fundamentally flawed

The fundamental flaw of animal-based research is referred to as ‘species differences’. Each species responds differently to substances, therefore animal tests are unreliable as a way to predict effects in humans.

Further difficulties are that distress caused to animals purely by being in the laboratory can affect the outcome of the experiment; test results can be affected by the animal’s age, diet, sex, even its bedding material; results from the same tests on the same species can vary from laboratory to laboratory; artificial, laboratory-induced disease is also different from natural disease.

Animal testing:


A rat in a UK laboratory has a probe permanently implanted into its brain. The experiment involved a drug which had already been given to five million patients worldwide. The same technique has been used to examine the effect on rats’ brains of the street drug, ecstasy.


  • Morphine drugs are a depressant in rats, dogs, hamsters and other species, but produce tremors and convulsions at comparable doses in mice and cats.
  • Penicillin is a useful antibiotic for people but it kills guinea pigs.
  • Guinea pigs can only breathe through their noses.
  • A drug used successfully for Legionnaires’ disease in humans did not prevent deaths in infected guinea pigs.
  • The breast cancer drug tamoxifen was designed as an oral contraceptive. It is in rats, but in women it has the opposite effect. It is now used in the treatment of breast cancer, despite causing cancer in rats in some studies.
  • Rats and mice cannot vomit.
  • The cancer drug 6-azauridine can be used in humans for long periods, but in dogs small doses produce potentially lethal results in a few days.
  • Phenylbutazone works through the body slowly in humans, but in dogs it disappears in hours.


The introduction of blood transfusion was delayed over 200 years because of misleading results of animal experiments. The introduction of corneal transplants was delayed nearly 90 years by misleading animal tests.

After a project using 18,000 mice, Teropterin was used to treat acute childhood leukaemia, but the children died more quickly than if they had not been treated at all.

The heart drug, Eraldin was thoroughly studied in animals and satisfied the regulatory authorities. None of the animal tests warned of the serious side effects in people, such as blindness, growths, stomach troubles, and joint pains.

Opren, the anti-arthritis drug, was passed safe in animal tests. It was withdrawn after causing more than 70 deaths, and serious side effects in 3,500 other people, including damage to the skin, eyes, circulation, liver and kidneys.



Contrary to what you might be led to believe by animal experimenters, the majority of medical and scientific research does not involve animals. Today there is a wealth of sophisticated techniques including computer modelling, tissue cultures, epidemiological studies (studying people and their environment), and clinical studies. Studies of direct relevance to people. And, there is a long history of medical progress without the use of animals.

Artificial Hip - the inventor, John Charnley, refused to experiment on animals. The hip which he developed is still regarded as the ‘gold standard’ by orthopaedic surgeons.

Childhood (acute) Leukaemia drug - the first effective drugs for childhood leukaemia were introduced in the 1940s, through study on patients. They were not tested on animal leukaemias until after they were shown to be useful in people. Methotrexate, one of those drugs, is still important in the treatment of childhood leukaemia and other cancers.

Asthma drug - sodium cromoglycate (Intal) is used to prevent asthma. It was discovered by a doctor who had little faith in animal experiments. He was allergic to guinea pigs so he exposed himself to them to induce asthma attacks, against which he tested over 600 new drugs.

More examples of medical progress without the use of animals:

Anaesthetics - introduction of chloroform, ether, nitrous oxide, and cocaine.

Asepsis - understanding of sterile techniques in surgery.

Blood - understanding of the blood groups and Rhesus factor.

Circulation - understanding of how the blood circulates around the body.

Drugs - introduction of beta blockers for blood pressure; digitalis for heart failure; morphine as a pain killer; nitrite drugs for angina; quinine for malaria; salicylic acid, the active ingredient of aspirin.

Epidemiology - discovery of the link between cancer and smoking; the causes of heart disease; and the causes of many other diseases.

Hormones - identification and purification of insulin for diabetes.

Surgical procedures - removal of the appendix; removal of bladder stones; Brock’s technique for blue baby surgery and mitral stenosis; repair of cardiac aneurysm; removal of cataracts; removal of gall stones; repair of inguinal hernia; removal of the ovaries for tumours.

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