A juvenile raccoon was euthanized because of severe neurologic signs. At postmortem examination, no significant gross lesions were present. Histologic evaluation demonstrated nonsuppurative encephalitis in thalamus, brainstem, and hippocampus, cerebellar Purkinje cell loss, as well as poliomyelitis and demyelination of the spinal cord. Parvovirus antigen–specific immunohistochemistry revealed immunopositive neurons in the brainstem, cerebral cortex, and hippocampus. A few Purkinje cells were also immunopositive. DNA extracted from formalin-fixed, paraffin-embedded brain tissue (thalamus, hippocampus, cerebral cortex) yielded a positive signal using PCR targeting both feline and canine parvovirus. Sequencing analyses from a fragment of the NS1 gene and a portion of the VP2 gene confirmed the presence of DNA of a recent canine parvovirus variant (CPV-2a–like virus) in the cerebellum. Our case provides evidence that a recent canine parvovirus (CPV) strain (Carnivore protoparvovirus 1) can infect cerebral and diencephalic neurons and cause encephalitis in an otherwise healthy raccoon. Parvovirus-induced encephalitis is a differential diagnosis of rabies and canine distemper in raccoons with neurologic signs.

由于严重的神经系统症状，一只幼年浣熊被安乐死。尸检时，没有明显的肉眼损伤。组织学评估显示丘脑、脑干和海马出现非化脓性脑炎，小脑浦肯野细胞丢失，以及脊髓灰质炎和脊髓脱髓鞘。细小病毒抗原特异性免疫组织化学显示脑干、大脑皮层和海马中的免疫阳性神经元。一些浦肯野细胞也呈免疫阳性。从福尔马林固定、石蜡包埋的脑组织（丘脑、海马、大脑皮层）中提取的 DNA 使用针对猫科动物和犬科动物细小病毒的 PCR 产生阳性信号。对 NS1 基因片段和部分 VP2 基因的测序分析证实了小脑中存在最近的犬细小病毒变异体（CPV-2a 样病毒）的 DNA。我们的案例提供的证据表明，最近的一种犬细小病毒 (CPV) 毒株 (食肉动物原细小病毒 1 ) 可以感染大脑和间脑神经元，并在其他方面健康的浣熊中引起脑炎。细小病毒引起的脑炎是对有神经系统症状的浣熊狂犬病和犬瘟热的鉴别诊断。