"Vivisection is barbaric, useless, and a hindrance to scientific progress. There are, in fact, only two categories of doctors and scientists who are not opposed to vivisection: those who don’t know enough about it, and those who make money from it."
Dr. Werner Hartinger, M.D., German surgeon, 1989

Let's see why animal testing cannot give any relevant results for humans.

Some differences between species may be evident (anatomy, morphology, behavior, etc.) while others can only be detected with scientific instruments (genetics, metabolism, physiology, etc.).

Genetic differences

Each species has a unique genetic heritage. The human body has between 20,000 and 25,000 genes and each gene consists of a sequence of molecules (ACGT bases) used to manufacture a particular protein, which provides a biological function in our body.

Sometimes two species have similarities but they are never sufficient to allow these species to serve as a biological model for another.

The human genome and the chimpanzee's are similar to 98.76%. The human genome contains several billion bases and a single base can cause spectacular biological effects (eg hemophilia). So, imagine the potential differences when 1.24% of the bases, several tens of millions, differ (see box).

Differences between individuals

The human population is a heterogeneous group in which there is great variability among individuals. A person can be affected differently by a single toxic dose, and the same person can react differently at different times of his life.

Two main types of factors help to explain the nature and extent of toxic effects.

Hereditary factors. Differences in the genes may play a role in people's ability to metabolise toxics.
The physiological factors which are many and include:

• Age: the sensitivity to toxic effects is different in infants, young children and the elderly
• Sex
• Nutritional status: the toxicity may be influenced by the mass of adipose tissue, dehydration, vitamin deficiency ...
• Pregnancy: it produces changes in the metabolic activity of the body and therefore of xenobiotics during pregnancy
• Health: healthy individuals are more resistant because they metabolize and eliminate toxins more readily than those with liver or kidney damage, where these two phenomena take place respectively.

However, toxicologists and researchers use animals in chemical testing and in biomedical research. They then try to extrapolate their results to humans.

Extrapolation of results to humans

To study a disease that exists only in humans (AIDS, human cancers, Alzheimer's, etc..) animals are modified to mimic the disease. Some are genetically manipulated to introduce defects, others undergo invasive surgery to damage an organ (eg laboratories and universities try to recreate parkinsonism in primates by damaging parts of their brain).

The research process can be summarized as follows:

• Observation of a pathology in human patients.
• Creating a resembling disease in the animals.
• Finding a treatment for the imitated pathology.
• Attempts to extrapolate the remedy to humans.

Human diseases are usually related to our lifestyle and more rarely to a genetic problem. Trying to recreate symptoms of a human disease in animals, that do not spontaneously develop our disease, is a waste of time and money. The results are not transferable to humans and can even be dangerous. To protect and heal the human, we must use methods based on human data. They are ethical, reliable and inexpensive, opposed to animal testing. See their description in "good science".

Examples of differences that distinguish species from each other

• Aspirin is the most commonly used drug in the world, yet it is fatal for 99% of all animal species. Luckily, this substance was discovered before that animal testing came into effect. If researchers had tested it on animals, they would simply have deprived Humanity from one of the most useful medicines.
• A sheep can ingest as much arsenic as it wishes without suffering any consequences.
• Rabbits can eat Amanita phalloides.
• Parsley kills parrots.
• A handful of almonds can kill a fox.
• Lemon juice is fatal to the cat.
• Morphine, which calms and soothes humans, makes rats and cats go into mad agitation.
• Penicillin is lethal for guinea pigs.
• For nearly 120 years, cats, dogs and monkeys are subject to continuous tobacco testing. They are forced to inhale smoke between 6 and 10 hours per day, between 5 and 7 days per week depending on the laboratories. These animals are blocked by the neck and masks constantly send cigarette smoke into their lungs. Unlike humans, none of these animals have developed lung cancer.

Would you ever take veterinary drugs to heal an illness ?
Would you try to give some of your medicine to the family cat ?