Assessment of cardiovascular disease in the donkey: clinical, echocardiographic and pathological observations

The Donkey Sanctuary (DS) owns 3500–4000 donkeys, estimated to be about 35 per cent of the UK population. Although postmortem surveys suggest a high prevalence of cardiovascular disease in donkeys, there is sparse clinical information about cardiovascular examination findings and echocardiographic findings in health and disease. In this cross-sectional study, auscultation findings were recorded, and in a subset of donkeys, echocardiography was used to screen for structural and functional cardiac disease. 202 donkeys were examined; 117 geldings and 85 females. Heart sounds S1 and S2 were detected in all donkeys, but none had audible S3. S4 was detected in nine (4.5 per cent; significantly older than those without S4; P<0.001). A heart murmur was detected in four donkeys. Echocardiography identified these to be due to a ventricular septal defect in one, and aortic regurgitation in three. An additional 43 donkeys had echocardiography. A further 10 donkeys were identified to have aortic insufficiency, but no other valvular regurgitation. 76/202 donkeys subsequently underwent postmortem examination. Three showed degenerative aortic valve changes. One donkey had nodular lesions in the intima of proximal aorta and sinus of Valsalva. Histopathology showed multifocal chronic nodular eosinophilic arteritis, consistent with verminous arteritis. The Donkey Sanctuary pathology database identified other similar cases.