Animal testing. After reading those words an opinion immediately develops in your brain revolving around past knowledge of the subject. Most people already have a developed opinion revolving around animal testing. People can see it as a positive, something that is going to advance the medical field and go to develop new cures for many different diseases. Others see it as a negative, something that is harming millions of different animals worldwide and providing no new benefits towards advancing the medical field. This paper explores both sides of animal testing, the positives and the negatives. This paper dives into the anatomical differences in both humans and animals which has led to the many mishaps with developing medicine through animal testing, the cruel and inhumane methods used, the alternative methods, and animal testings astonishing accomplishments over the years. Overall this paper strives to expose the reader to a new side of this issue and to hopefully get the reader to reconsider the opinion that was first developed when reading the words, animal testing.

Animal testing is not a new phenomenon, it has been around for years. Descriptions of the dissection of animals have been found in ancient Greek writings from as early as 500 BC. Physician-scientists such as Aristotle, Herophilus, and Erasistratus performed these experiments in order to discover the functions of living organisms.Through these early experiments, there were many new discoveries about how the human body functions. For example, Roman physician and philosopher Galen (130-200 AD), demonstrated that arteries, which were believed by earlier physicians to contain air, actually contained blood. Also, English Physician William Harvey (1578-1657) discovered that the heart, and not the lungs, circulated blood throughout the body as a result of his experiments on living animals.

Animal testing was only seen as a positive because people believed that animals could not feel or think. This all changed in the 19th century with the increased amount of domestic animals. This was the moment when two opinions develop revolving animal testing, the people against it and the people for it. This lead to some early advancements in restricting the amount of animal testing being used such as the Great Britain’s Cruelty to Animals Act of 1876. Today, animal testing is still prevalent in society, but the fight against it is just as strong. The development of new regulations and groups such as PETA work to restrict and regulate the many aspects of animal testing. However, an estimated 26 million animals are still used every year in the United States for scientific and commercial testing. The animals are used to develop medical treatments, determine the toxicity of medications, check the safety of products destined for human use, and other biomedical, commercial, and health care uses.

One of the flaws to animal testing is that drugs that have been tested on animals are not necessarily safe for human use due to anatomical differences. Many different species of animals are used for testing in order to determine the safety and effectiveness of many medicines and chemicals. Some of these animals do have similar anatomical structure to humans, but none of these animals have the exact same structure. We share approximately 99% of our DNA with mice. Researchers can use mice to see what effects specific genes can have on human bodies. They are able to do this by “turning off” specific genes in a mouse and looking at what effects turning them on and off would have on the body. (“The animal model: Biological”). The amount of DNA that we do share with certain species of animals is very high and does go to show that there are many similarities in the anatomical structure between animals and humans. However, the differences in anatomical structure is of more concern when trying to translate the results and effects given by testing medicine on animal into how human bodies may react.  

Many researchers have been studying the similarities between mice and humans in order to see if mice are an accurate enough model to test for human diseases. They found that gene regulation and other systems important to mammalian biology have many similarities between mice and humans. However there are some small differences in many DNA variations and gene expression patterns. For example, the regulatory elements and activity of many genes of the immune system, metabolic processes, and stress response vary between mice and humans. (“Comparing the mouse and human genomes.”). Another specific difference between mice and humans anatomical structure is the pancreas of both mice and humans differ greatly. The human pancreas consists of the head, the body, and the tail. While the mouse pancreas has 3 lobes that are less well defined: the duodenal, the gastric, and the splenic lobe which are not present in the human pancreas. When looking at a microscope it is easy to identify that humans have larger lobules than the mouse. (Dolenšek, Slak Rupnik, Stožer, (“ Structural similarities and differences”). These small differences can make a big impact when trying to produce medicine and chemicals to the public because if there is a difference in how certain parts of the body functions then there is a potential that there will be a difference in how the body will react.

It is also important to consider that mice are not the only animals that important medicine is tested on. Animals such as monkeys, birds, rabbits, and guinea pigs are also being used in these testings. These animals also share a large amount of DNA with humans, but have their own anatomical differences with humans that can pose issues when testing. There have been many instances where a drug or a chemical was tested on animals and the results given were not the results that occured in humans. This can be dangerous because a drug that is given out could potentially be harmful for humans without anyone knowing because it wasn't harmful for the animals that it was tested on. Events like this have occured in the past with the result being long lasting effects on the humans who took the medicine or was exposed to the chemical.

Thalidomide was a drug released in the early 1960s and was a mild sleeping pill that was advertised as being safe enough for pregnant women to use. However, thalidomide caused an estimated 10,000 birth defects most commonly known as phocomelia (the failure of the limbs to develop). This drug was released to the public because it was tested in animals and did not result in birth defects and death unless given at very high quantities. (“The Tragedy of Thalidomide,”) Many people are still affected by the release of thalidomide in the 1960s. This goes to show how animal testing can not be as reliable because there are anatomical differences that will affect the outcome of how different medicines and chemicals affect the body. This tragedy occured because there was a anatomical difference between humans and the animals being tested which then resulted in thousands of people to be affected.

Another example of animal testing failing to be reliable because of the anatomical differences between humans and animals is with Vioxx. Vioxx was an arthritis drug that went to cause 27,000 heart attacks and various cardiac deaths. This drug was released in the first place because when it was tested on mice, it was deemed effective in reducing arthritis pain. However in this case the results from the animal testing did not translate to humans and caused many deaths and injuries. (“Should Animals be used,”). There have been many more examples, with the outcomes not being as tragic, of anatomical differences causing difference results in humans than in animals. This raises the question if animal testing is a reliable source to determine if medicine and chemicals are safe for human use.

Animal testing involves many cruel and inhumane methods that lead to dangerous health effects to a variety of animals. “Cruel and inhumane” methods can be defined as any method that goes to harm the animal when there are other options to limit pain inflicted upon it. One example of one of these methods is the Draize eye test. The Draize eye test is mainly used by cosmetics companies who want to test certain cosmetic ingredients. This method involves clipping rabbits eyelids open, for many days. The technician drops the product in their eyes and the clips prevents the rabbit from blinking away the product. (“Should animals be used for scientific,”). This can cause pain and discomfort to the animal all for the testing of cosmetics. Another example of a cruel testing method is exemplified while testing the effects of toxoplasmosis on kittens. The kittens are used for research in toxoplasmosis, a parasitic illness that mainly affects unborn babies and people with weak immune systems. The kittens are fed infected meat in order to test the parasites eggs. The cats are usually killed after research because they are deemed as unsafe for adoption. (“Animal testing: US senate bill,” December 20, 2018).

While, there are laws and agencies in place for protecting animals, but there is little regulation of these laws which allow for cruel animal testing to still occur. The Animal Welfare Act which excludes some 95 percent of the animals that are commonly tested on, such as rats, mice, birds, fish, and reptiles. The law however only provides minimal protections for the rest (“Federal Law and Agencies,”). This is one issue for animals because there are laws in place to protect them from cruel and inhumane methods, but the most tested on animal, mice, does not get these protections. As well as not providing protection, the Animal Welfare Act has obvious loopholes which allows for any procedure or protocol to be allowed as long as the researcher can state a “scientific need” for using animals in that manner to advance human health. For example, the AWA requires that researchers provide pain-relieving medication to the tested animals in order to minimize the pain or distress from the conducted experiment. However, the pain relieving medication can be withheld if it is deemed “scientifically necessary.” (“Laws and Regulations.”). These loopholes make it hard for animals to get the protections that are applied in the laws. Also agencies are very similar to the laws that are set in place currently. Protection agencies are supposed to protect the animals being used regularly and make sure that cruel methods don’t occur. One agency that has some of the most issues is the United States Department of Agriculture. This is the federal agency that oversees and inspects laboratories that experiment on animals and locations who breed and sell animals for use in laboratories. From the description of the agency, it seems like it would be successful in providing protection, but the issue is there are only 115 USDA inspectors to oversee more than 7,750 licensed facilities. This makes adequate inspection and regulation of these facilities close to impossible. Also when the USDA does finds facilities that are not following AWA regulations, they will issue penalties which are typically very small. This allows for facilities to keep breaking the AWA regulations because there is no real consequence (“Federal Law and Agencies,”).  

There are many other alternative methods of testing drugs and chemicals that don't involve animals which have proven to be just as accurate. Traditional animal testing methods have been accurate for most of the time, but as discussed previously, these methods have been shown to not be as accurate because of anatomical differences. These new alternative methods are proven to be just as accurate as the traditional methods, but eliminates the use of animals. These testing options are a better choice because they are less expensive to perform as well as not causing harm to millions of animals.

One example of a alternative testing method is in-vitro testing. A test performed in vitro (latin: "in the glass") means that it is done outside of a living organism and it usually involves isolated tissues, organs or cells.You can use in vitro data to fully or partly fulfil information requirements that would otherwise need data to be generated with tests on living organisms (ECHA, In vitro methods).  In-vitro testing is also known as organs-on-chips. The chips contain human cells that are grown to mimic the structure and function of human organs and organ systems. The chips can be used to replicate human physiology, diseases, and response to drugs. (“Alternatives to animal testing.”). This type of testing is starting to be used more as the various benefits of it are starting to be discovered.

Another method that is becoming more popular as its benefits are being discovered is computer modeling. Computer modeling is a computer that is able to simulate human biology and developing diseases. Studies have shown that these computer models can predict how the drug will work in the body and what the reaction will be. Also it is shown that this testing method can replace testing on animals and standard drug tests. (“Alternatives to animal testing.”). By implementing computer modeling in the place of animal testing, scientists are able to see how the drug would react on a human body. Therefore this can be a more accurate form of measurement because it is not looking at an animals organ system which can have some anatomical differences to the human body system. Another positive thing about computer modeling is this approach could also be applied to many more chemicals than animal testing this can lead to wider safety assessments. Due to costs and ethical challenges only a small fraction of the roughly 100,000 chemicals in consumer products have been comprehensively tested. While with computer modeling, a wider range of chemicals can be safely tested, this would overall branch out our knowledge about different types of chemicals and their effects on humans. (Global Biotech Insights, 2018).

Along with computer modeling and in-vitro testing there is another method that avoids animal testing, but it proven to be just as accurate. This method is human-patient simulators. The human-patient simulators are able to breathe, talk, bleed, and even simulate death. These simulators can be used to mimic developing diseases and injuries. The simulator is also able to give appropriate biological responses to the diseases and injuries and can respond to the medication given. (“Alternatives to animal testing.”). This simulator would change chemical and medicine testing completely. This testing does not involve animals, but is able to supply scientists with a direct look into how a chemical, disease, injury, or new medicine will affect the body.  Human-patient simulators are even starting to be used, PETA and medical doctors from Northwestern University School of Medicine and Harvard Medical School met with senior federal government officials and did a demonstration at the MedStar Health Simulation Training & Education Lab (SiTEL) in Baltimore, MD, about the benefits of replacing animal use in trauma training with advanced human patient simulators, including a demo of two prototypes, Caesar and TraumaMan (PETA, Alternatives to Animal Testing).

However it is important to notice that animal testing has been and important factor to how these alternative methods have been developed. Animal testing has provided us with enough knowledge about chemical and medicine reactions that we were able to use that information to develop new and improved methods.

Despite having many downsides, such as inhumane methods and inaccuracy due to anatomical differences, animal testing has changed the development of medicine for the better. Over the years, animal testing has allowed for new discoveries in medicine, chemicals, and cosmetics that have led us to all the knowledge that we now know about the human body and toxicity. Without animal testing, the development of antibiotics, vaccines, blood transfusions, dialysis, organ transplants, chemotherapy, bypass surgery or joint replacement would have taken a lot longer to be used in the medical field. Everyone has benefitted from animal testing and research. In fact, practically every drug, treatment, medical device, diagnostic tool or cure used today was developed with the help of lab animals (“How Animal Testing and Research”). This means that animal testing has really gone above and beyond to advance the medical field despite the negative thoughts about it. However animal testing is still doing its job and is currently working to prevent diseases and develop vaccines. Many diseases that once killed millions of people every year are now either preventable, treatable or have been eradicated altogether. Immunizations against polio, diphtheria, mumps, rubella and hepatitis save countless lives and the survival rates for many major diseases are at an all-time high thanks to the discovery of new drugs and the design of sophisticated medical devices and surgical procedures.  In the coming years, a universal influenza vaccine may be a reality, as well as a vaccine to end the HIV/AIDS pandemic. (“How Animal Testing and Research”).

Research with cows helped create the world’s first vaccine, which in turn helped end smallpox. Studies with monkeys, dogs, and mice led to the polio vaccine. Drugs used to combat cancer, HIV/AIDS, Alzheimer’s, hepatitis, and malaria would not have been possible without research with primates (“How Animal Testing and Research”). One specific example of how animal testing contributed to a life-saving cures, treatments, or development is Asthma Inhalers. Inhalers, both reliever and preventer, were developed through research on guinea pigs and frogs. One in ten children currently receive treatment for asthma. This was an amazing discovery and would not have been made possible without the use of animal testing. (“Animal Research Benefits Us and Animals,”). Another example is animal testings work in diabetes, The treatment of diabetes with insulin has been studied using dogs and rabbits. Insulin research has lead to helping many animals and people with diabetes.  (“Animal Research Benefits Us and Animals,”). Also the incredible work with animals led scientists to discover organ transplants which has gone to save millions of lives. Organ transplants were developed through the testing of animals. Specifically, heart and kidney transplant techniques and vital anti-rejection medication were developed using experiments on animals. This development has helped the lives of so many people. In 2009-2010, 3,700 people received major organ transplants (“Animal Research Benefits Us and Animals,”).   

Overall the goal of this paper was to get the reader to see both sides of the issue and reevaluate what they first think when discussing animal testing. However, after reading the paper the reader should have identified that animal testing is a complicated issue to develop an opinion on because of the many different positive and negative aspects. Everyone has benefitted from animal testing and research, it has gone to provide vaccines, knowledge about the human body, knowledge about toxicity, and much more. However there is still a negative stigma around it due to inhumane methods being used and the lack of accuracy. This makes it very difficult to choose an opinion that reflects either supporting or opposing animal testing. Nevertheless, the increase of new knowledge gained about both sides of the dilemma can be used to help spread to the public that animal testing is not a one sided issue. It is an issue with both pros and cons, with both downsides and upsides, with both positives and negatives, overall an issue with many sides.

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