Every year Californians relinquish approximately 1 million cats and dogs to animal shelters and pounds, where nearly 70 percent of those animals are eventually euthanized. Hoping to identify what goes wrong in those pet-owner relationships, an assistant professor from the UC Davis School of Veterinary Medicine has launched a survey of pet owners who turn in animals to shelters, as well as pet owners randomly interviewed at local shopping centers. "The Sacramento Overpopulation Study or S.O.S. is aimed at identifying characteristics, such as pet behavioral problems or unrealistic owner expectations, that influence and may even predict the success or failure of the relationship," says Dr. Philip Kass, a veterinary epidemiologist. As part of a national study, S.O.S. is intended to guide veterinarians and animal control officials in designing educational programs that will help owners deal with some of the problems and prevent the massive euthanization of cats and dogs.