Additional cases of pericarditis are occurring in Kentucky and possibly other states (including Ohio), with the problem now claiming lives. Pericarditis is an inflammation of, and fluid in, the sac that surrounds the heart. Dr. Doug Byars, head of the internal medicine unit at Hagyard-Davidson-McGee (HDM) veterinary firm in Lexington, Ky., said veterinarians at his clinic and those at Rood and Riddle Equine Hospital are starting to see horses previously treated for pericarditis returning to the clinics with more heart problems."This is becoming clinically significant," said Byars, "and some of the horses are starting to wind up in necropsy."Byars added that some equine practitioners are starting to define this syndrome as an "epicarditis," which describes inflammation in a layer on the outside of the heart, not necessarily in the pericardial sac around the heart. "These can have a bleak prognosis," he added.There were five new cases of pericarditis seen at the HDM medicine clinic last week in addition to the horses previously diagnosed and returning with additional heart problems."This is looming as a problem that needs to be considered for the upcoming sales and beyond," Byars said. "It's a significant situation." Byars recommends that horse owners and farm managers keep a close eye on horses of all ages and genders. Watch for unexplained fever, lethargy, signs that indicate pneumonia, distention and pulsing of the jugular veins in the neck, and muffled heart sounds. A veterinarian should use ultrasound to diagnose the problem and institute treatment immediately, which might include draining fluid from around the heart.