On July 31, 2004, a 278 cm male juvenile Risso's dolphin (Grampus griesus) was reported stranded at Cape Henlopen State Park, Sussex County Delaware. Following initial triage by the Marine Education, Research & Rehabilitation Institute (MERR) ground transport was arranged to the Riverhead Foundation for Marine Research and Preservation at the Atlantis Marine World Aquarium, Riverhead New York. Clinical signs on admit included thin body condition, excessive buoyancy, respiratory congestion and superficial lacerations and abrasions secondary to stranding and transport. Serum neutralization tests for morbillivirus antibody indicated positive titers for dolphin morbillivirus (DMV) ranging from 12 to 48. RT-PCR testing methods to detect the presence of morbillivirus in peripheral blood leukocytes yielded negative results. The analysis of serology and RT-PCR ruled out an active infection and viremia and instead likely indicated past exposure to dolphin morbillivirus (DMV).
On April 13, 2005, the first successfully rehabilitated Risso's dolphin was released following 8 months of rehabilitation. Prior to release a SPLASH Sharkfin Model 210-000 satellite tag and VHF transmitter tag were attached to the dorsal fin. The Riverhead Foundation is presently collecting post-release movement and diving profile data with initial analysis indicating movements coinciding with known habitat utilization of the species.