Search teams aided by tracking dogs gave up a three-day search for a mountain lion that attacked and seriously injured a 6-year-old Huntington Beach boy last weekend at the Ronald W. Caspers Wilderness Park near San Juan Capistrano. "The trails simply went cold and the dogs seemed to have lost interest," said Tony Gimbrone, district supervisor for Orange County parks. "We are convinced that, as of this moment, there is not a single cougar in the park." County officials said the park will remain closed, but rangers will continue to monitor trails and, if a cougar is sighted, state game wardens will be notified immediately. Meanwhile, the mauling victim, first-grader Justin Mellon, received a rabies shot, had a talk with a psychologist and "came home in high spirits," his father, Timothy Mellon, 28, said.