Animal models have been used for studies and have been helpful in understanding life and diseases. However, there are ethical and scientific issues when using these models since they are indeed separate species. Since not all animals are the same and humans are different from other animals, there can be issues when using them. A rat’s body is going to be extremely different compared to a human’s body, down to the number of chromosomes. Animals models are not as good as we think due to the physiological differences between other animals and humans, the limitations in understanding diseases, a lack of applying what we see to a human scale, and the restriction of using mostly male animals. However, there are benefits when using animal models, such as, using animal models to look at certain symptoms, the ability to easily test certain diseases, improvement of experimental drugs, and disease progression.
The difference in body functions and shape should be enough to discourage researchers from putting papers out there claiming that certain things are harmful to health. This creates a panic within people, especially when it is something like Red40 or Seed oils. These studies use animal models, mostly rats, and then we can conclude that these effects could also happen on humans. They do this without giving a specific amount, when in reality, you would need lots of these “harmful” things to see any effect. This is a limitation on animal models. We can’t completely correlate what happens to a rat to what would happen to a human. The scale of models also matters. How many rats were used, and how could the same disease or issue spread to humans? Most models also use one gender of the animal and not both most of the time. Female and male animals are just as different as female and male humans. Females tend to have much more diverse and intricate bodies, especially when it comes to hormones. How can we properly use these models to study animals if we only use male models?
Another limitation would be trying to understand diseases. An example of this is how cats and humans differ in how diseases such as herpes affect both species. Herpes in humans present with blisters on and around the mouth. There are two forms in humans, genital and oral. In cats, herpes usually presents as an upper respiratory infection. There can be issues with the eyes, sneezing, or discharge from the nose. The only true thing they have in common is that the subject is infected for life. We cannot rely on animal models when it comes to these specific diseases.
The benefits of animal testing include using these models and studies to understand certain symptoms in the animal and how they might apply to a human. Certain animals do have similar reactions to certain drugs and based off of that, we can assume how they will react to diseases. We can also easily test certain diseases that we don’t fully understand. Infecting an animal with the disease can give us deeper insight on how infection may spread and spread within cells. We can also see how certain diseases progress within the animal and what their symptoms may be. With these infected individuals we can try new drugs to help their symptoms or completely cure their illness. Before we test these drugs on humans, we need to see the side effects and using animal models would be a good way to do that without harming anyone. There are lots of ways to do this exact thing.
The alternatives for animal models include microfluidic organs-on chips and 3D organoids. These alternatives help see the features and functions of a cell on a 3D scale. These two methods use human-derived induced pluripotent stem cells (Kwon, 2026). These cells have been programmed to act like stem cells, which means they can become many types of cells. Scientists can use these cells to create miniature human organs, organoids. There is also a way to take these cells and create organ-on-chips that mimic the function of human tissues (Kwon, 2026). When they are able to create biological functions that occur naturally in the body. With these models, we can observe and research the functions. These models also make a better environment for study due to them being human cells. The animal models are of other animals and so the information we get might not be as accurate. This provides a way to understand how human cells specifically react to specific drugs and chemicals without the worry that there might be a slight difference in how a rat reacts as opposed to a human.
There are also current methods that use computational models and generative artificial intelligence. These are becoming more common when trying to understand chemical and toxicology outcomes in live animals. These technologies analyze humans and lab data to predict whether chemicals are likely to have harmful effects on humans such as skin sensitivity (Kwon, 2026). Generative AI can enhance predictions by generating a circumstance of exposure to see how a human’s body would react. While these models are not completely accurate, they do reduce the need for animal testing and accelerate research to become more relevant to humans.
There are some drawbacks when it comes to these new approach methodologies due to the fact that they are reductionist systems (Kwon, 2026). Most organs-on-chips can only focus on one organ or a specific limit of biological functions. They cannot replicate a whole body’s systems and how they interact with each other. They cannot replicate communication between organs and systems. The models can also not replicate active aging that normal humans have and can’t replicate hormone systems. Computational models also have issues if the data they are processing isn’t complete or even accurate. This makes it unable to fully predict interactions.
All of these models do represent a huge advancement in technology and scientific research. Cutting down on animal models is very impressive since they have been around so long. By using iPSC’s, scientists are able to look at more specific organs of humans and how their bodies respond to certain chemicals. This allows for breakthroughs in studying drug safety. While the challenges still exist, there will always be improvements that will always be made as long as technology allows it.
Sources:
Kwon, D. (2026). The age of animal experiments is waning. Where will science go next?. Nature, 650(8103), 812–814. https://doi.org/10.1038/d41586-026-00563-3