Animal research plays a crucial role in scientists' understanding of diseases and in the development of effective medical treatments.

Research animals provide scientists with complex living systems consisting of cells, tissues and organs.  Animal models can interact and react to stimuli, giving researchers a picture of a compound moving through a living system and an idea of how that stimuli might react in a human being.  Animals are biologically similar to humans in many ways and they are vulnerable to over 200 of the same health problems.  This makes them an effective model for researchers to study.

Mouse Held By ResearcherThe majority of research animals are used in experiments focused on disease treatment and prevention, and the treatment of injuries.  Laboratory animals are also used in basic medical research, breeding other research animals and diagnosis. 

Rats and mice account for about 95 percent of all animals used in research.  Most of the remaining research animals are rabbits, guinea pigs, hamsters, farm animals, fish and insects.  Combined, less than one percent of the remaining research animals are cats, dogs and non-human primates.  The overwhelming majority of research animals are specifically bred for laboratories.  Understanding Animal Research has a timeline of medical progress and the role animals have played.

Before conducting research on animals, scientists make absolutely certain animals are needed for their experiments.  For more than 50 years, scientists have relied on the "3Rs": refinement of tests so animal distress or pain is minimal, reduction of the number of animals used in one particular study, and the replacement, whenever possible, of animal experiments with non-animal experiments.

For more information on animal research, visit Understanding Animal Research at