A research colony of beagles whose ancestors proved vital to a low-level radiation research project that spanned more than three decades was closed this week at the Institute of Toxicology and Environmental Health at the University of California, Davis, with most of the dogs finding new homes. Through an agreement with the university, the Marin County Humane Society assumed ownership of 180 animals over the past two months, picking up the last beagles this week. So far, homes have been found for nearly all of the beagles. A drop in demand by researchers for the animals prompted the university to reduce the size of the breeding colony and finally close it. Forty-seven animals have been transferred to other campus facilities as part of biomedical research projects that include studies of Alzheimer's disease and leukemia. "The contributions to health research of projects involving this specialized colony have led to higher quality medical care and standards," said Robert Shelton, vice chancellor for research. "Now that these studies are complete, it is particularly gratifying to see the successful placement of these dogs by the Marin County Humane Society." The University of California has had a longstanding relationship with the society, which uses a regional network to identify homes for former research animals. The society offered its services to UC Davis when it heard the campus was deciding the future of the colony. The colony was established in the 1950s to investigate the biological effects of X-rays. It then became part of a 33-year project at the former Laboratory for Energy-Related Health Research (now ITEH) investigating the health effects of exposure to low-level radiation. Researchers chose beagles as animal models for this work because of their long life spans and their physiological similarities to humans. The last beagle associated with the program, funded by the Department of Energy, died in 1986 at the age of 18 1/2. -more- 2-2-2 Colony Closed Since then, the colony has provided valuable support for health and biomedical studies, as well as nutritional studies. Some of the animals have served as blood donors for the Veterinary Medicine Teaching Hospital. All of the dogs given to the humane society were in good health but had never experienced a home environment. Initially, campus officials had reservations about placing the kennel-raised animals in private homes because of the dogs' special needs. They have since been impressed by the dedication and professionalism of the humane society workers, and have expressed confidence that the animals will find good homes.