Nasitrema Species: A Frequent Culprit in Melon-Headed Whale (Peponocephala electra) Strandings in Trinidad.

Five melon-headed whales (Peponocephala electra) were reported as single strandings on the beaches of the eastern (Atlantic) coast of the Caribbean island of Trinidad between March 2013 and November 2015. We examined four of the five reported cases. Animals displayed a loss of equilibrium and repeatedly restranded following reflotation attempts. One animal died naturally at the stranding site, while three were euthanized after unsuccessful reflotation attempts. Eggs and/or adult trematodes (Nasitrema species) were identified in the brain of all cases and were generally associated with multifocal moderate pyogranulomatous meningoencephalitis. Peritoneal parasitic (cestode) cysts, gastrointestinal helminthiasis, and ulcerative gastritis associated with anisakid nematode infestation were also common findings across specimens. To date, no other stranded cetaceans examined on the island have been similarly affected. The findings presented herein strongly suggest that Nasitrema species-associated encephalitis is a common cause of melon-headed whale strandings in the southeastern Caribbean. [ABSTRACT FROM AUTHOR]