Department of Veterinary Population Medicine/Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Minnesota, St. Paul, MN.
Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY.
J Vet Diagn Invest. 2021 Jan;33(1):140-143. doi: 10.1177/1040638720967381. Epub 2020 Oct 26.
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 () 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.
一只幼年浣熊因严重的神经症状被实施安乐死。剖检时，未发现明显的大体病变。组织学评估显示丘脑、脑干和海马有非化脓性脑炎，小脑浦肯野细胞缺失，以及脊髓灰质炎和脱髓鞘病变。细小病毒抗原特异性免疫组化显示脑干、大脑皮层和海马的免疫阳性神经元。少数浦肯野细胞也呈免疫阳性。从小鼠脑组织（丘脑、海马、大脑皮层）提取的福尔马林固定、石蜡包埋的 DNA 使用针对猫细小病毒和犬细小病毒的 PCR 检测呈阳性信号。从 NS1 基因片段和 VP2 基因的一部分进行测序分析，证实小脑中存在一种近期犬细小病毒变异株（CPV-2a 样病毒）的 DNA。本病例提供的证据表明，一种近期的犬细小病毒（CPV）株（）可感染大脑和间脑神经元，并导致浣熊出现脑炎。在有神经症状的浣熊中，细小病毒引起的脑炎是狂犬病和犬瘟热的鉴别诊断。
