We lost one of our wild dolphins of South Padre Island some years ago to a stingray barb in his heart.
We found Pilgrim washed ashore in the Laguna Madre Bay very sick. He was brought to the Coastal Studies Lab and put in one of the holding tanks and the vet and marine mammal stranding group was called in. The dolphin could not swim on his own and seemed in extreme pain, especially when trying to nibble his fish. He died when being fed a fish which put pressure on the area that the barb was penetrating (Usually there is a death roll and any one in the tank with the sick dolphin has to be careful not to be hit by the dying dolphin.)
The vet from the Glady's Porter Zoo let Seth help with the necropsy. They found, at the stomach, there was a large sore that had healed over. They followed the scar tissue which led a path thru the young male's stomach and then on thru his lung and finally in his heart they found the barb of a stingray.
This dolphin had lived for quite sometime,in pain, while this barb always on a forward path with its serrated edges, made the journey thru his body and unfortunately into his heart instead of out of his body by a harmless route.
We are not sure of how he encountered the stingray so that the barb entered his body, but he may well have swam over this stringray in shallow water and surprised the ray into the defense mode and more than just the tip of the barb entered the dolphin. Enough of it entered that it pulled out of the stingray and into the dolphin's stomach area. Any family member trying to help would not be able to pull the barb out. It would now have to travel thru his body.
It is a sad ending for this dolphin and a very rare event.