The unusual mortality events (UMEs) among striped dolphins suggest that parasitic diseases may be increasing in the open ocean due to anthropogenic causes. In addition, case reports indicate nematodes present in the brain of the striped dolphin, described as a single round and thin worm with numerous eggs in the subcortical lesions, including the optic nerve. It is hypothesized this worm belongs to the genus Contracaecum, the same genus which has been reported to infect the brains of sea lions. Caution should be employed when handling these animals due to the possibility of a serious injury if the right steps are not taken in order to ensure both human and animal safety.