Correct diagnosis of cause of death is necessary to suggest the most effective management interventions to reduce perinatal lamb mortality. Haemorrhage on the surface of the brain has been used as a field diagnostic tool to allocate lambs to a cause of death category, but the usefulness of this method was unclear. This study aimed to evaluate whether gross pathology was related to neuronal death and whether haemorrhage of the central nervous system (CNS) was distinct between differing causes of death, enabling indicators to be used in field diagnoses. Lambs dying from natural causes (n = 64) and from euthanasia (n = 7) underwent postmortem examination, then the brain and spinal cord were extracted and examined histologically. Histological changes consistent with neuronal death were not detected in any lamb. Haemorrhage of the meninges and/or parenchyma of the CNS occurred in all lambs. The age of the haemorrhage indicated that it occurred near the time of death in most lambs. Dilation of blood vessels varied in severity but appeared to be unrelated to causal diagnosis, severity of subcutaneous oedema, breathing or milk status. Moderate or severe dilation of blood vessels and haemorrhage of the CNS did not occur in all lambs with alternative clear indicators of dystocia and occurred in all death classifications, so it could not be used as diagnostic indicators for classification of cause of death. Dilation and haemorrhage were unrelated to neuronal damage and may have been artefactual. In conclusion, haemorrhage of the CNS was not indicative of neuronal damage and could not be used to distinguish between lambs with clear indicators of differing causes of death, so it is not recommended as a field diagnostic tool.

正确诊断死亡原因对于建议降低围产期羔羊死亡率的最有效的管理干预措施是必要的。脑表面的出血已被用作现场诊断工具，以将羔羊分配到死因类别，但这种方法的用途尚不清楚。这项研究旨在评估总体病理学是否与神经元死亡有关，以及中枢神经系统出血（CNS）在不同的死亡原因之间是否有明显区别，从而可以将指标用于现场诊断。死于自然原因的羔羊（n = 64）和安乐死（n= 7）进行死后检查，然后取出脑和脊髓并进行组织学检查。在任何羔羊中均未发现符合神经元死亡的组织学变化。所有小羊都发生中枢神经系统的脑膜和/或实质出血。出血年龄表明，大多数羊羔死于出血时间。血管扩张的程度不同，但似乎与因果诊断，皮下水肿的严重程度，呼吸或乳汁状况无关。在所有具有其他明确的难产指标的羔羊中，并未发生中度或重度血管扩张和中枢神经系统出血，并且在所有死亡分类中均未发生，因此不能将其用作死亡原因分类的诊断指标。扩张和出血与神经元损伤无关，可能是人工制品。总之，中枢神经系统出血并不表示神经元受损，不能用于区分具有不同死因的明确指标的羔羊，因此不建议将其作为现场诊断工具。