Chester Zoo chimps help global heart disease research
Chester Zoo is leading an international study into heart disease among great apes.
Vets at Chester Zoo are working with scientists at Cardiff Metropolitan University to investigate a link between life in captivity and heart disease.
Dylan, a 25-year-old chimpanzee, is one of the apes taking part in the study.
He has gone under general anaesthetic so Chester Zoo vets can do medical tests on his heart.