Observations on vascular accidents in the central nervous system of neonatal foals.

A technique for the subarachnoid perfusion-fixation of the central nervous system was developed to help identify various significant vascular accidents (SVAs) in the central nervous system (CNS) of 24 neonatal foals submitted for necropsy. SVAs, comprising subarachnoid, parenchymal and nerve root haemorrhages, and oedema and necrosis, occurred in 17 foals, more frequently in the spinal cord than the brain. They occurred as frequently in premature foals as in those born at full term, in foals born dead as in foals born alive, and in foals born following dystocia with an assisted delivery as in foals born unassisted. Eight of the live foals showed neurological signs. Those with syndromes of cerebral disease tended to have brain SVAs, whilst all 3 with signs of spinal cord disease had SVAs restricted to the spinal cord. No association between the SVAs and other specific disease processes was detected in these foals although 2 premature foals born dead with equine herpesvirus-1 infection did have spinal cord SVAs only. A similar distribution of brain and/or spinal cord SVAs was detected in the foals born dead as in the live foals, but the lesions were more severe. It is concluded that the birth process itself may be a major factor in the development of SVAs and that some affected foals may exhibit a syndrome referable to spinal cord involvement.