The Care of Use of Animals in Biomedical Research

(Taken from Unit II, Chapter 2, of the Rx for Science Literacy teacher manual.)

Human beings use animals for a wide variety of purposes, including research. The approximately 260 million people in the United States keep about 60 million cats and about 52 million dogs as pets. Including birds and horses, just these types of American pets total nearly 130 million. More than five billion animals are consumed each year as food. It’s estimated that about 17 million animals are used for biomedical research annually.

In research, animals are used to learn more about biological systems and the illnesses that afflict human beings and other animals. They serve as surrogates for humans in obtaining information that cannot be gained in any other way. For example, advances in genetic engineering have made it possible to create genetically identical animals, enabling researchers to compare different procedures or treatments on identical animals. Some animals have biological similarities to humans that make them particularly good models for specific diseases such as rats for cancer, rabbits for atherosclerosis and monkeys for polio.

If human beings had chosen to stop using animals for medical research 100 years ago, the world would be a very different place today. The biological information acquired through the process of research has unlocked the secrets of genetics, shed light on the workings of the brain and made it possible to understand new diseases like AIDS. Many of us are alive and healthy today because of the knowledge gained from animal research, which has controlled many diseases. Even the animals that we keep as pets would live shorter, less healthy lives were it not for many of the vaccines and treatments that have become standard in today’s veterinary medicine.

Animals are used in biomedical research because:
  • It is not ethical to test substances or drugs with unknown and potentially adverse side effects on humans. Imagine being the first to try a drug that had not been tested on any living system.
  • Controlled experiments necessitate introducing only one variable at a time. Animal populations are easily controlled in a laboratory setting. Human environments and genetic backgrounds vary widely, which makes it difficult to control variables.
  • There is no substitute for the living systems necessary to study interaction among cells, tissues and organs. Animals are the best surrogates because of their similarities to humans, both in structure and function of their organs and biological systems.
  • Shorter life spans of animals enable scientists to study effects over shorter time periods. Rats have a life span of two to three years. A more rapid rate of reproduction also allows for several generations to be studied in shorter time periods than in human life spans.

Past tragedies have caused permanent damage and even death to people using products or medicines that did not have adequate animal testing. Some examples:

  • In the early 1930s, an untested eyelash dye called “Lash Lure” was introduced to the market in the United States. The product contained a substance called p-phenylenediamine, which sensitized ocular structures, leading to corneal ulceration and resulting in a loss of vision and at least one fatality.

  • In 1937, an antibacterial medicine was sold in the United States as a liquid dissolved in diethylene glycol (antifreeze). Antifreeze is toxic; this resulted in the deaths of 107 people.

  • As recently as the 1980s, a teflon-coated disk, which was implanted into the jaws of thousands of patients with TMJ (temporomandibular joint syndrome) had to be removed. This device was breaking into microscopic fragments, causing a biochemical reaction in patients that eroded the jaw bone. Animal studies were not done until after reports of the failures began in 1984.

    Before 1976, medical devices such as these jaw implants did not require approval from the FDA before being marketed. Today, in addition to requiring FDA approval prior to being introduced to the market, many medical devices undergo extensive laboratory tests, animal experiments and human clinical trials involving groups of closely monitored patients.

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