Establishing death in stranded Odontocetes (toothed whales) using other mammals : a pilot study : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Zoology at Massey University

Abstract

The aim of this study was to investigate and evaluate a new method for determining death in stranded odontocetes (toothed whales). The new method was using the pulsations seen in the retinal blood vessels in the place of the heart rate. The retinal blood vessels can visualized, using an ophthalmoscope, in the fundus of the eye. Initially the procedure was to be testing using animals at a mass stranding, but there were no suitable strandings that took place during the time of the study. Therefore other mammal species were used to test the procedure. These mammals were cattle, sheep, and dogs, with additional observational testing carried out on seals, sea lions and dolphins. The mammals were chosen because of their availability and supply. The results showed that there was a strong relationship between the heart rate and the pulsations measured in the retinal blood vessels. This was expected as the cardiovascular system is connected and pulsations of blood vessels must have originated from the heart. The results using dogs, also indicated that there is a relationship between the cessation of the pulsations in the retinal blood vessels and the cessation of the heart beat. Dogs were used as a benchmark by which all other mammals could be compared. Therefore this study indicates that it is possible to identify the cessation of the heart using the cessation of the pulsations in the retinal blood vessels,