Experimental animals: THE 3R RULE

Evita Apalaki

These days, the voices against animal testing are very loud. Activists, animal organizations and individual animal lovers protest in the name of animal rights, trying to prevent them from being used in experiments. In fact, there is ancient evidence showing that curiosity led humans to start exploring life through animals. The history indicates the first attempts of the ancient Greek philosophers Aristotle and Erasistratus started experimenting on animals as early as BC. Similarly, Galen’s dissections of pigs and goats have been documented in manuscripts. Even if there is a big portion of the population that is opposed to experiments on animals, it is a fact that apart from the knowledge gained on the biological systems of organisms, the vast majority, if not all, of the deadly diseases (like HIV, Alzheimer, malaria etc) have been prevented through such methods. Animals are still the most important part of in vivo experiments in the contemporary scientific world. However, there is a strict legal background that tries to protect animal welfare while simultaneously promoting the production of high-quality level sciences. The basic principles of animal testing are summarized in the simple, but important, rule of the 3Rs. 

According to this triple rule, REDUCTION of experimental animals is one of the parameters that needs to be taken in consideration. An experiment has to be well scheduled before it begins. Only if animals are important for the study, then only the necessary minimum should be included. A well-programmed protocol can reach accurate estimations about how many animals are needed in order to obtain conclusive results. This REDUCTION step also includes the sub-rule that one animal should take part in more than one study, if possible. In that way, the useless scarification of multiple animals is avoided. Even if the experiments of a lab include a limited set of tests, young and healthy animals could be given to other researchers so that they can participate in additional studies. Also, the planned experiments should initially start by retrieving results from single trials. Reducing the repetition of the experiments can help to reduce the number of needed animals. 

REFINEMENT is the second rule of the 3Rs. In the case that animals are necessary for the realization of the tests, they should be included in the studies in which their security and welfare can be assured by following a specific list of steps. First of all, their environment has to be safe and appropriate for their species, including being cleaned regularly. Animals should not be isolated in their cages (unless it is a parameter of the experiment), and males should be separated from females in order to avoid unexpected mating or aggressiveness. Also, their cages need to include triggering equipment like games, rolls, shavings and hiding places for them. In this way, animals feel more comfortable and have the opportunity to be more active during their day. Of course, it is of vital importance for both their health and the accurate experimental results to feed the animals with good-quality food and water. In parallel, the practical aspects of the experiments should also follow specific requirements. Medication and painkillers should be provided to animals that are in pain or seem to have poor health conditions. Any invasive acts, like surgeries, should take place after having anesthetized the animal and extensive care needs to be provided during recovery. Finally, if animals seem to be in extreme pain, have signs of relapse or intense signs of suffering, they need to be euthanized after anesthesia. 

At this point, it is necessary to mention that animals should only be handled by a qualified and well-educated staff. Beginners and students are usually guided by the professionals of an animal facility and all medical processes, as well as the health of the animals, should always be checked by licensed vets. An experienced scientist that participates in animal testing should also be a good observer. There are behavioral and external signs that indicate negative signs in the well-being and health condition of an animal, like self-isolation, aggressiveness, decreased appetite, lack of grooming willingness or body wounds -usually related to animal violence in a cage- that signify an unfavorable condition for the animal. Animals should always be respected and gently handled. The third and equally important rule of the 3Rs is the REPLACEMENT of animals in science. Even if it is impossible to completely exclude animal testing from ongoing scientific research, there are cases that require computational models to be as equally conclusive as animal experiments. The level of technology and bioinformatics has reached such intellectual levels that new scientific questions can now be solved through virtual experiments. Already existing results of previous animal related studies are enough to create huge databases that render continued animal testing useless. These protocols are based on computer work mainly (dry lab research) though the results are “blood-free”. Furthermore, cell culture models and microorganisms can 100% be efficient alternatives for in vitro lab experiments that help the reduction of the total number of animals used for research purposes. 

Undoubtedly, animal testing hasn’t stopped providing invaluable knowledge to the scientific community since antiquity. Humanity owes a big “thanks” to all the animals that have been sacrificed in order to find new vaccines, treatments and medications for low or high-risk diseases. Countries have already demonstrated that the protection of animal rights is important by creating strict legislation. The 3Rs explained above is a simple rule of thumb. It is a strategy that needs to be followed by all the laboratories and scientific centers in order to keep the total number of animals that are sacrificed per year for medical research purposes balanced. It seems as though the future is promising and new technologies may be possible to partially or completely replace animal models.