Is animal testing a necessary evil? - Experiments and tests on animals happen in labs every day. Several scientists and researchers argue that this is one of the best methods to test substances, products, and chemical components that could be harmful to humans.

But what about the lives of the various animals subjected to these tests? The issue has led to various protests around the world and although alternatives are not abundant, they do exist.

Click on the gallery and get to know more about animal testing.

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Pros - Animal testing has resulted in several discoveries and cures for diseases that otherwise would have never been possible. For example, according to animal-testing.procon.org, tests where the pancreas was removed from several dogs led to the discovery of insulin, which is critical to the lives of diabetics.

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Cons - Animal experiments are often cruel. The species tested are subjected to force feeding, inhalation of harmful fumes, deprivation of water and food, prolonged periods of physical restraints, burns, and injuries.

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No clear alternative - There is still no alternative method to test an entire functional biological system without using animals or people. Even the most advanced computers in the world are not yet able to predict how one of the most complex organs in the human body, such as the brain, will react.

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What are the alternatives? - For some testing, it is already possible to not have to use any type of living organism. In vitro tests are used to study cells and are able to produce better results than tests done on animals. This is because with in vitro tests, it is possible to study human cells directly and obtain concrete results.

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Are these animals that similar to humans? - Species, such as chimpanzees, share about 99% of their DNA with humans and mice about 98%. These animals are subject to the same diseases because they share so many biological similarities with humans.

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Use of chimpanzees - The US and Gabon are the only countries that allow experiments on this species.

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Pain - The US Department of Agriculture stated in 2010 that 97,125 animals suffered pain during experiments because they were not administered anesthesia.

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Failed tests - In the 1950s, a sleeping medicine, called thalidomide, was put on the market. The drug caused more than 10,000 birth abnormalities and was tested on animals before being marketed.

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Expenditure - According to animal-testing.procon.org, the US alone spends about $14 billion annually on research and animal testing.

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Body parts - Scientists Joseph and Charles Vacanti were able to reproduce a human ear from cow cartilage cells that were implanted in a mouse. This experiment served to explore the possibility of making new body parts to aid in reconstructive surgeries.

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What scientists say - According to a 2011 survey conducted by the scientific journal Nature, 90% of the 1000 biomedical scientists surveyed approved the use of animals in lab tests.

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Efficiency rate - It is estimated that about 92% of the drugs found to be safe for animals fail when tested on humans because they are too dangerous, or simply don't have the desired effect.

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Withdrawn from the market - Recent studies indicate that about 50% of drugs are taken off the market after five years due to unexpected side effects.

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Cosmetics - Europe, Israel, and India have banned the use of animal testing for cosmetic products as well as the import and sale of products tested on animals.

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HIV vaccine - Several HIV vaccines have been tested and found successful in primates, however, all have failed to take effect in humans.

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Animal Welfare Act (AWA) - About 95% of the animals used in experiments are not protected by this law. This is because it excludes birds, mice, and cold-blooded animals, such as reptiles and most fish.

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Not protected - Even though certain animals are included and supposedly protected by this law, it hasn't necessarily prevented them from being used in tests.

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Quantity - According to the Humane Society, the development of a successful pesticide requires about 50 experiments and the use of 12,000 animals.

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Overdose - These animal tests are frequent. Animals are given large amounts of a chemical to determine the dose that can lead to death.

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Food safety - Animals are fed enormous amounts of food for weeks or months in order to determine whether the product is safe for human consumption.

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Strong argument - The California Biomedical Research Association states that almost all medical advances made in the last 100 years have been the direct result of animal testing.

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Animals also benefit - Several diseases that are now controlled or eradicated in several species are also the direct result of animal testing.

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Alternative testing - Several animal rights institutions and organizations advocate alternative tests with three important points: replacing the animal testing process, reducing the number of species used, and using pain-free methods.

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The countries that test the most - At the top of the list of countries using animals in experiments are the United States, Japan, China, Australia, the United Kingdom, Germany, and Brazil.

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High risk for humans - Cruelty Free indicates that human testing had to be stopped during a Hepatitis B study because five patients died from liver complications. The same drugs used by humans had been tested on animals without any consequences.

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Aspirin - Aspirin is toxic in mice and cats and would have most likely never existed if it had been tested on animals first. Fortunately, it wasn't.

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Opinion - How about you? What do you think about animal testing? Do you think it is crucial for the future of medicine or that it should be stopped as soon as possible?

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