Western lowland gorillas are critically endangered, with populations further threatened by respiratory disease outbreaks that can spread rapidly through social groups. Ebola virus has killed thousands of gorillas in Central and West Africa.
Gorillas infected with Ebola experience acute haemorrhagic disease with extremely high mortality and significant suffering. Respiratory infections cause distress and reduced feeding that impairs condition in social groups. Disease spread through dense social groups is rapid once infection enters. Veterinary monitoring of habituated groups enables treatment of some conditions but cannot prevent Ebola outbreaks. The welfare harm of disease in great apes is amplified by their high cognitive and emotional complexity.