Why Use Animals? Biomedical Research

Non-animal and non-human models Consider each of the following models. What are some reasons these models might not provide all the information needed to confirm if a new drug or medical device is safe and effective for us to use? A computer model of how a drug is metabolized in the body 2. A human tissue sample to study if a new chemical causes cancer (is the drug carcinogenic) 3. Yeast cells used to check if a new drug is toxic to parts of a cell

Using Animals Research helps us : understand how our body functions (physiology) understand diseases that affect us (pathology)

Using Animals Despite the difference in appearance between humans and animals, we share similar biology. Mice are around 99% genetically similar to humans.

Animals in Research Used to learn more about biological systems and the illnesses that afflict human beings and other animals Serve as surrogates for humans in obtaining information that cannot be gained in any other way Not ethical to test substances or drugs with unknown and potentially adverse side effects on humans

Using Animals Even if we give a new medicine to some human cells, this cannot tell us how it will affect the whole body. Living animals, most commonly mice, rats and fish, are used to see how a medicine affects a whole body. We also need to know if the medicine will reach the part of the body it needs to. Animals can tell us about the toxicity and will also indicate what dosage is necessary for humans.

Animals in Research ANIMAL SYSTEM/CONDITION Cats Auditory Primates Immune Dogs Cardiovascular Endocrine Mice Aging Rats

Percentage of Animals About 25 million animals are used for research each year in the US. About 95% are Mice or Rats About 3% are guinea pigs, rabbits, or hamsters 0.28% Primates 0.25 % Dogs 0.08% Cats >1% Other species

Where do we get Animals for Research Most animals are bred specifically Breeding allows scientists to control specific traits in animals.

Where do we get Animals for Research The Animal Welfare Act (AWA)permits use of dogs and cats from local shelters but due to restrictive legislation this rarely occurs Some non endangered species are imported for use in research. Endangered species such as the chimpanzee are NOT used in research.

Three Rs of Research Refinement – Finding ways to make research animals’ lives better. ie: toys for animals or better training for technicians Reduction – Using less animals, only enough to get good results Replacement – Using non-animal alternatives whenever possible

Decreasing Animal Use Dogs= 67% decrease since 1973 Cats=68% decrease since 1973 Guinea Pigs=48% decrease since 1973 Hamsters=68% decrease since 1973 Rabbits=53% decrease since 1973

What do you think? Researchers also try to use the “lowest” type of animal possible for their experiment – for example: a fish instead of a sheep or a fruit fly instead of a mouse. Why do you think scientists try to replace animal use? Why use “lower” animals – do you agree with this idea?

What do you think? TIMELINE ACTIVITY

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