FREQUENTLY ASKED QUESTIONS
The Care of Use of Animals in Biomedical Research

  8. Why Use Animals?
  9. What are the Most Commonly Used Animal Models?
10. Which Animals are Studied for their Unique Characteristics?
11. Where Would We Be Without Animal Research?
12. Man’s Best Friend ... and Research Partner
13. How Many and What Kinds of Animals are Used in Biomedical Research?
14. How are Animals Used in Biomedical Research Cared For?
15. What Laws, Regulations and Guidelines Govern Animal Research?

FAQ — General Questions (1-7)

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13. HOW MANY AND WHAT KINDS OF ANIMALS ARE USED IN BIOMEDICAL RESEARCH?
(Taken from Unit II, Chapter 4 of the Rx for Science Literacy teacher manual.)

Research studies are carefully designed and conducted to yield scientifically reliable results, using as few animals as possible. The most frequently cited estimate of the total number of animals used in research and testing in this country is between 17 and 22 million. More than 90 percent of these animals are rodents, whose short life span, ease of breeding and similarity to human biology fit many scientific purposes. Moreover, scientists can now breed mice and rats with genetic alterations that mimic human diseases, which have revolutionized medical research. Genetically altered rodents have allowed researchers to observe what happens during the progression of Parkinson’s disease, cancer, cystic fibrosis, heart disease, memory loss, muscular dystrophy and spinal cord injuries.

Other animals used in research come from many different species — fish, sheep, cows, horses, pigs, armadillos, goats, etc. — depending on the biological functions being studied. The choice of species is a carefully thought-out process. Even what seems like the most unlikely species may be used to satisfy particular requirements. For example, crayfish are used to study muscle functions. Armadillos are used to study leprosy. Pigs are used to study influenza and to develop new surgical techniques. Woodchucks infected with a virus similar to the human hepatitis B virus are ideal models to study new treatments for the disease. Because they share anatomic similarities with humans, sheep are becoming popular models to study diseases and injuries of the bones, joints and muscles. The squid, octopus and sea snail are important models for neurobiological studies. For instance, researchers using the giant axon of the squid have unlocked the secrets of how human brain cells work. Also, leeches share a protein with humans, which is a key component in memory and permits scientists to study the cellular basis of simple behavior.

Less than one percent of animals used in medical research are cats and dogs, which are often used to study the nervous and circulatory systems. Fewer than 0.5 percent are nonhuman primates such as monkeys, which are of particular importance in studying the brain and in developing human vaccines.

Most animals used in medical research are specifically bred for research. Some studies require animals that have a known genetic history and specific traits, and breeding animals allows scientists to control those traits. Also, due to restrictive legislation in some states, unwanted animals in city pounds may not be released for research, even though their use in medical research would produce benefits to humans and animals. Nothing is gained from their routine destruction. In fact, for each dog or cat used in research, 100 abandoned animals are killed in pounds and shelters.

In a few cases, nonendangered species of wild animals are imported into the United States for use in research. Endangered species such as chimpanzees are protected by international agreements; no chimpanzees have been imported for research since the 1970s.

Did you know that:

• Ninety-five percent of all animals used in medical research are rats, mice or other rodents specifically bred for research.
  
  
• Valid and useful scientific findings are obtainable only when research animals are healthy and protected from undue stress.
  
  
• Federal regulations prohibit both animal abuse and use of sick, injured or distressed animals as research subjects.
  
  
• The majority of animal studies use medical techniques similar to those used on humans. They involve little or no pain to the animals.
  
  
• Humans are also often used as research subjects.
  
  
• Research animals are carefully selected to ensure that only the number and species essential to each research project is used.
  
  
• Most research animals are bred specifically for that purpose.
  

Below is a comparison of the 1998 figures concerning the numbers and kinds of animals used with those from the first reporting year of 1973:

• Dogs: The number used in FY 1998 represents a 61 percent decline since FY 1973.
  
• Cats: The number used has dropped 62 percent since FY 1973.
  
• Guinea pigs: Use is down 36 percent since FY 1973.
  
• Hamsters: Use has dropped 54 percent since FY 1973.
  
• Rabbits: The number used has declined 35 percent since FY 1973.
  

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