Dr. David Waters, DVM, poses with Kyrie, Robin Lohse’s 15-year-old Rottweiler, in Homer at the start on March 4 of his Grey Muzzle Tour, a national tour where the veterinarian visits geriatric Rottweilers across the country to assess their health as part of a study on aging and cancer resistance. Waters is the director of the Center for Exceptional Longevity Studies at the Gerald P. Murphy Cancer Foundation, West Lafayette, Ind. Many Rottweilers die of cancer, but long-lived Rottweilers somehow resist cancer, even though autopsies show most had some cancer when they died. “It was really fascinating talking to him,” Lohse said of Waters. “He’s really smart and really driven.” Lohse lives in Homer.