With animals, scientists come the closest to assessing the biologic reactions and responses found in people. General functions of cells, blood and tissues are the same in animals. The similarities let scientists observe diseases such as heart disease, diabetes, many different types of cancer and hemophilia in animals. Observing how animals develop and fight disease and respond to potential treatments provides valuable knowledge. In addition, even if an animal’s biology differs from human biology, examining the differences can increase our understanding of the human body.
Computer models and cell cultures, as well as other adjunct research methods, are excellent avenues for reducing the number of animals used. These methods are used to screen and determine the toxic potential of a substance in the early stages of investigation, thereby reducing the total number of research animals needed. The final test, however, has to be done in a whole, living system. Even the most sophisticated technology cannot mimic the complicated interactions among cells, tissues and organs that occur in humans and animals. Scientists must understand these interactions before introducing a new treatment or substance or procedure into humans.
Animals get many diseases similar to ones that affect people. By studying these animals, medical researchers can learn what causes diseases and how to prevent, treat, or cure them. These findings help both humans and animals. Researchers also study animals to understand how they adapt to different environments. This can help threatened or endangered species