Stranded dolphins’ brains show common signs of Alzheimer’s disease

The brains of three different species of stranded dolphins show classic markers of human Alzheimer's disease, according to the most extensive study into dementia in odontocetes (toothed whales). The new pan-Scotland research, a collaboration between the University of Glasgow, the Universities of St Andrews and Edinburgh and the Moredun Research Institute, studied the brains of 22 odontocetes which had all been stranded in Scottish coastal waters. The study, which is published in the European Journal of Neuroscience, included five different species - Risso's dolphins, long-finned pilot whales, white-beaked dolphins, harbour porpoises and bottlenose dolphins - and found that four animals from different dolphin species had some of the brain changes associated with Alzheimer's disease in humans. The findings may provide a possible answer to unexplained live-stranding events in some odontocete species. Study authors confirm the results could support the 'sick-leader' theory, whereby an otherwise healthy pod of animals find themselves in dangerously shallow waters after following a group leader who may have become confused or lost. Whales, dolphins and porpoises are regularly stranded around the coasts of the UK. They are often found stranded in groups, or pods, in shallow waters and sometimes on beaches.