3R's - Refinement

In the world of animal research, "refinement" refers to methods to reduce possible stress or discomfort to the animals involved. It also encompasses measures to improve animals' overall well-being and environment.

For example, new technology allows researchers in some experiments to monitor or image animals' internal organs without the need for surgery. If surgery is necessary, anesthesia combined with new and more effective sedatives and analgesics - pain-relieving drugs - minimizes animal anxiety and discomfort.

One of the ways the CNPRC supports the refinement effort is through the use of state-of-the-art noninvasive imaging techniques. The CNPRC has had a long-standing commitment to using various imaging tools such as ultrasonography, which uses high-frequency sound waves to image deep structures of the body. Recently, the CNPRC, through a collaborative effort with UC Davis biomedical engineering faculty, acquired a microPET (positron emission tomography) scanner. A microPET is similar to PET scanners used in most human medical facilities, only smaller. MicroPET imaging allows scientists to study a wide range of physiologic functions while significantly minimizing manipulation of the animal, and reduces the numbers of animals required for studies.

Such efforts follow the philosophy and guidelines outlined in 1959 by Rex Burch and William Russell, authors of The Principles of Humane Experimental Technique. Their book remains a guidepost for humane animal research to this day.

Burch and Russell maintained that giving due consideration to issues of animal welfare is not just important from an ethical standpoint, but also a matter of good science. Proper care of research animals is critical to good experimental design.

Refinement also applies to developing humane "endpoints" for experiments. An endpoint is the point at which a test or experiment is considered complete. Medical technologies such as magnetic resonance imaging and computer-aided tomography allow scientists to detect tumor growth and organ deterioration early on and to gather other information from an experiment without requiring the animal to progress to later stages of disease. This reduces suffering and can lower the number of animals needed for certain types of tests.

Russell and Burch believed that humane care and treatment of animals used in research extends beyond their involvement in experiments. Refinement applies to all aspects of the life of a laboratory animal. This includes providing housing appropriate for a particular animal species and applying techniques for enriching their environment to enhance psychological well-being and promote natural behavior.

For example, tree-dwelling monkeys in captivity typically would be housed in a cage containing multiple perches and allowing vertical movement. To accommodate monkeys' highly social nature, animal care staff attempt to house monkeys with a partner or in a group whenever possible.

Creative measures are taken to try to simulate monkeys' natural foraging behavior. Animal care staff members have fashioned a number of ingenious devices, such as foraging boards and puzzle balls, that require the animals to extract their food from rows of cavities in a plastic board or through holes in a plastic ball. The activity requires dexterity and concentration and prolongs the time spent feeding.

The California National Primate Research Center employs a comprehensive approach to animal care. The CNPRC recognizes that an important component of animal health is psychological well-being in addition to proper nutrition, sanitation and veterinary care. Behavioral management is an inherent part of the Center's Animal Care Program, which focuses on social companionship and environmental enrichment to enhance the monkeys' quality of life.