Survey of retinal haemorrhages in neonatal thoroughbred foals

Twenty-seven of 167 neonatal thoroughbred foals (16 per cent) were found to have retinal haemorrhages after a careful examination of the entire fundus. Experience in differentiating haemorrhages from other lesions, and the selection of foals from normal populations, were considered to have an important effect on their apparent incidence. Bilateral haemorrhages were more common and there was a significantly higher incidence in female foals. The numbers of haemorrhages ranged between one and 20; 36 per cent of eyes with retinal haemorrhages had the small punctate type and 56 per cent had the splash-like form. There was no change from one type of haemorrhage to another, and the patterns of resolution were similar. The haemorrhages were in the tapetal fundus, except two that were recorded in the optic disc, and they resolved within 10 days. No short- or long-term ocular or neurological effects of the retinal haemorrhages were detected, and they were not related to the incidence of abnormal foal behaviour.