World Day for Laboratory Animals 24 April

Instituted in 1979 World Day for Laboratory Animals, and the associated Lab Animal Week, has been a catalyst for the movement to end the suffering of animals in laboratories around the world and their replacement with advanced scientific non-animal techniques.  The suffering of millions of animals all over the world is commemorated on every continent. Find out how you can get involved and help lab animals here.


Although advanced methods are steadily replacing animal research, outdated laws require animal tests before a product can be put on the market. Every year millions of animals suffer and die in experiments that can never be trusted.

As a method of predicting likely effects in humans, animal research is flawed in three key areas:

  • ‘Species differences’. Each species responds differently to substances, therefore animal tests are an unreliable way to predict effects in humans.
  • Human diseases in laboratory animals are not naturally occurring so need to be artificially created; they are different from the human condition they are attempting to mimic. This also affects results.
  • Studies have shown that living in a laboratory environment can affect the outcome of an experiment, with test results differing due to the animal’s age, sex, diet and even their bedding material. So results vary from laboratory to laboratory.

Government and agency regulators who are responsible for allowing products on the market, are used to these standard animal tests and the estimates and ‘safety’ evaluations drawn from them. They are also aware of the potential for species differences, which may result in injury to people.  Thus, a series of animal tests is followed by human trials and this is where the problem of species differences can produce unexpected adverse reactions in people.

Some examples of horrific and unexpected side effects in people, due to differences in reaction between species include:

BIA 10-2474 Drug Trial. Clinical trials with a new drug, BIA 10-2474, went fatally wrong – when given to human volunteers – one died, four showed evidence of brain damage and it has since been reported that another lost his fingers and toes. The product had been tested on mice, rats, rabbits, dogs and monkeys for toxic effects on various organs as well as reproductive toxicity. Monkeys were given doses approx 75x that given to the human volunteers. See full report here. 

TGN1412 – an experimental drug was given to human volunteers and caused life-threatening reactions, yet monkeys were given doses 500 times higher than the human volunteers and no side effects had been seen.  This disaster may have been avoided with the implementation of advanced technologies such as ‘micro dosing’ with spectrometry analysis.

Species Differences

Animal species differ from each other in a number of ways. For example:

  • Non-human primates are distinct from us in the way they express genes in the brain. There are even big differences in gene expression between humans and chimps, although gene expression between chimps and other non-human primates is similar
  • Monkeys are frequently used in brain experiments because of their apparent similarity to humans but they still differ from us in various ways including the structure of the nervous systems, sense organs and, evidence suggests, differences in how they function.
  • Macaque monkeys are frequently used in toxicology testing but they have specific genes which are vital for drug metabolism (when a drug works through the body). These genes are not found in humans and this is “partly responsible for differences in drug metabolism between monkeys and humans.
  • The blood clotting mechanisms of dogs are different from those of humans
  • Guinea pigs can only breathe through their noses
  • Rats, mice and rabbits cannot vomit
  • Zebrafish – a species increasingly used to model humans – has only two heart chambers whereas the human heart has four.

Species differences mean that animals used in research can give different results to humans:

  • Aspirin causes birth defects in monkeys, but is widely used by pregnant women without the same effect.
  • Parkinson’s disease only naturally exists in humans, so some of the main characteristics of the disease are not present in animals. Models are created by injecting toxins or creating genetically modified animals. But drugs found to be protective in the brain of animals, including primate models, are not effective in humans.
  • The anti-inflammatory drug Vioxx had unexpected effects on human patients, after laboratory animal tests. An estimated 88-140,000 extra heart attacks may have been caused by Vioxx causing up to 61,600 deaths.
  • 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.
  • Cancer drug Teropterin was tested on 18,000 mice. Used to treat acute childhood leukaemia, but 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.

Animal use is an outdated method

NAVS Institute of Neurology primate2_moderate

Advances in science and technology are evolving rapidly, providing advanced non-animal techniques that are faster, more accurate and of direct relevance to humans. There are a range of sophisticated, multidisciplinary techniques that allow the study of the effectiveness and safety of substances on human tissue in-vitro, as well as in humans. Non-animal methods also include computer analytics, database and models based on humans – better for science as well as humans and animals.

However, some animal researchers are resistant to moving away from the use of animals in research and towards non-animal alternatives.

Researchers at London’s Institute of Neurology have been carrying out invasive brain experiments in monkeys for four decades. An investigation conducted by our campaign partner the National Anti-Vivisection Society in 1996 documented monkeys with electrodes inserted into their brains  through their opened skull to study the nerve connections between the brain and hand muscles. These painful experiments continue today, while the same researchers also carry out studies in humans, without causing such pain and suffering.

Other researchers have shown that primate research is unnecessary, and that the same level of information can be obtained from human volunteers using non-invasive techniques such as MEG scanning. fMRI scanning also allows the study of neuron network in the brain, in ways previously only thought possible using invasive methods. Neuroimaging is contributing to the detailed mapping of the human brain, providing unprecedented understanding of functioning and development of mental ill health and neurodegenerative diseases.

Regulations for the safety testing of all products were originally devised based on animal methods. All over the world, the regulatory ‘tick box’ approach continues to this day. The fact that results vary between species and are inconsistent is well known but is, effectively, set aside. Many tests continue simply to comply with regulations, rather than for any scientific value.

Product testing regulations require that such testing must be carried out in at least two mammal species: a rodent species and a non-rodent “second species”. Animals are burnt, blinded, scalded, poisoned, mutilated, starved, and substances are forced down their throats through tubes, so that the products we use every day can be called “safe”. These may be things we use in our food (additives), in our home (cleaners, laundry etc.), in our cars, our gardens, and the medicines we take; everything has been tested on animals.

Household products ingredient testing in the UK includes using animals for “innovative benefit” or in line with chemical testing rules. Animals are used to test ingredients for items such as detergents, cleaning products, air fresheners, toilet cleaners, paints, and other decorating materials. Tests on animals for garden products such as pesticides are still allowed.

NAVS beagle UK_drug toxicity testing

Each year in Britain over 2,500 dogs and more than 2,200 monkeys are subjected to painful experiments to test the safety of different chemicals and drugs for human use. However, an analysis of animal toxicity data of over 3,000 drugs concluded that further data from the second species does not solve the problem of extrapolating results to humans.

ADI campaign partner, the NAVS undercover investigations in the 1980s and 90s of a number of laboratories carrying out safety testing on animals revealed dogs being force-fed weed killer. The dose was given through a rubber hose, pushed down each dog’s throat, directly into the stomach. Dogs were also subjected to Maximum Tolerated Dose studies, where animals are dosed to a level where they show signs of toxicity, such as a loss of weight and appetite, vomiting, diarrhoea and convulsions. The drug being tested was force-fed to restrained dogs before they were returned to their cages to vomit.

Many years later, the NAVS again documented the same suffering in experiments to test drugs in dogs, with side effects such as foaming at the mouth, vomiting, bleeding from the gums, and diarrhoea. Decades of suffering despite the highly questionable validity of these tests.

Likewise in the US, animals are used to test the safety of drugs and substances and for cosmetics testing, now banned in the UK and Europe. Although exact figures for animal experiments are unknown, latest statistics suggest over 825,000 animals, including nearly 72,000 primates and almost 45,000 dogs, are experimented on each year. The actual figure however is in the tens of millions as reporting omits the use of birds, mice, rats and fish – species given so little thought that they aren’t even covered under the US Animal Welfare Act.

Advanced techniques which do not rely upon animals, and concentrate on methods more relevant to humans are the way forward.

Replacing use of animals with advanced science

Animal tests can be replaced with advanced scientific methods that are faster and more relevant to people, therefore safer. See more here.

Toxicity testing on animals

How products you buy are tested for ‘safety’