This page focuses on the pro arguments concerning animal testing. For the con arguments, visit Group 7 Animal Studies.
The European Parliament enacted a directive that is a guideline for the use of animals in animal testing. Member states should act according to the ethical principle of replacement, reduction and refinement: [1]
- Replacement means that member states should use other scientifally satisfactory methods and should only use animals if no other way is possible.
- Reduction means that the specific goal of a project should be achieved by using a minimum of animals.
- Refinement means that during the entire use of animals in animal testing, the style of use should be refined as good as possible. This includes breeding, accomodation, care as well as the methods used in procedures. Refinement aims at reducing pain, suffering, distress and lasting harm to the minimum.
On the basis of the above direction, new animal study regulations lead to an increased difficulty for the use of animals and when animals are used, the new procedures put less stress on the them. [2]
Although the number of animals used for animal testing has mainly increased in the past 15 years, this is only due to an increased use of mice in the animal testing. The number of animals that are more sentient – like apes – could be reduced both in total and relative to the total number of used animals (cp. fig. 1). [3]
In the following three main arguments for animal testing are presented.
Figure 1: Numbers of used animals in Germany (in millions, new counting technique beginning from 2014 onwards) [3]
Animal testing is irreplaceable for new therapies and basic research
The translation of basic research into new medical therapies is not possible without the usage of animal testing as an intermediate step. To assess the effect of new drugs on an entire organism, the drugs must be either tested on animals or on humans. Without animal testing, new therapies must be directly tested in humans, which is hindered by the high desire for safety in modern societies. [2] It is an highly ethical question, too: shall risky new drugs be tested in humans and put their lives at stake if there is a possibility to make a first assessment of the drug's effects without any harm? Making a decision in favor of animal testing means protecting patients.
Moreover in basic research, animal trials cannot be replaced, as they are performed to gain new knowledge about the entire organism. The organ functions can only be observed in animals or humans and the observation from animal testing are very comparable to humans. [4] If animal testing was to be abolished, basic research would be severely confined and might move to countries with less restrictive laws concerning animal testing.
Cell cultures and computer simulations are less effective than animal testing
Tissue cultures and computer simulations can be alternatives to the use of animal testing, but there are several disadvantages compared to conventional animal testing. A main disadvantage of tissue cultures is the behavior of the cells in the culture: they do no longer behave like normal cells in organs, but act like degraded cells similar to tumor cells. This is especially true for neurology, where cell cultures do not act like cells in a brain. [4] This leads to specific medical procedures not being able to be validated in cell cultures. [2]
For creating good computer simulations, it is necessary to know the processes that are simulated. But scientists often do not know the exact biological processes and parameters during the animal study, so creating a realistic computer simulation is very difficult. [4] One of the disadvantages of animal testing is the bad translation to clinical trials (see next argument), which is mainly due to a lack of understanding and comparison of biological processes in different species. If it is not possible to predict the outcome with high accuracy, it is probably even harder to find all necessary parameters to compute an accurate outcome.
Additionally – as mentioned before – new drugs currently must be tested in animals before they are tested in clinical trials. This is done to test the drugs in an entire organism, but both cell cultures and computer simulations are no capable replacements for an entire organism. [2]
Despite bad translation to clinical trials, at least some severe side effects can be ruled out
Of the one third of successfull animal testing that enters clinical trials only 8% pass the Phase I study (cp. Clinical trials and new methods undergoing clinical trials). [5] Different studies show different prediction rates, in one study 4 of 24 toxicities were found because of the animal testing and in another 6 of 114 toxicities from clinical trials correlated with the preceded animal testing. [6] Although these numbers show a bad prediction capability, there were toxicities that were shown by the animal testing and therefore the animal testing can be called useful in these cases.
Conclusion
Animal testing still is widely spread and its use is still increasing. It is necessary to give scientists all possibilities to perform basic research even and especially by means of animal testing. Animal testing is a secure way to assess the effects of a new drug on an entire organism and therefore is highly necessary in the process of authorizing new drugs.
New technologies like cell cultures and computer simulations should be used according to the principle of replacement, reduction and refinement. They are good means to reduce animal testing and in some cases may replace it, too. But both technologies do not offer the same set of possibilities as animal testing and should not be considered as a complete replacement.
Especially regarding the bad translation to clinical trials of animal testing, new technologies should be used to increase the knowledge about animal biology and human biology to create better predictions of animal testing.
Kommentar
Unbekannter Benutzer (ga46zuy) sagt:
05.Juli 2017Nothing more to add, you made good points