Rabies-Like Neuronal Inclusions Associated with a Neoplastic Reticulosis in a Dog

Abstract. Neoplastic reticulosis of the central nervous system was associated with intracytoplasmic inclusion bodies in Purkinje cells and neurons of several nuclei. These eosinophilic inclusion bodies were from round to crescentic and had a different location, structure, and cytochemistry than Negri bodies and inclusions of other canine neurologic diseases. The inclusions represent an aberration of rough endoplasmic reticulum and resemble the cytoplasmic laminar bodies of the lateral geniculate neurons of the cat. Few neoplastic reticuloses of the central nervous system of dogs have been described [3]. None has been reported in which there was an apparent association with cytoplasmic inclusion bodies in neurons. The inclusion bodies resembled Negri bodies, and since fresh tissue for animal inoculation or fluorescent antibody techniques [5] was not available, histochemistry and electron microscopy were used in the differential diagnosis. Materials and Methods A o-year-old female Cocker Spaniel was seen by a veterinarian because of restlessness and continuous walking. She was examined again 3 days later because of marked depression. A blood sample was taken for a complete blood count and certain serum chemical determinations. The dog died 4 days after the initial visit. Formalin-fixed tissues submitted to our laboratory included pancreas, adrenal, esophagus, stomach, kidney, liver, lung, urinary bladder, small and large intestine, spleen, heart, uterus, and brain. Staining was done on 6-11m sections of paraffin-embedded tissue except for Sudan black B for which frozen sections were used. The staining methods used to study the inclusion bodies are summarized in table 1. Additional stains for study of the infiltrative cells were Gomori's methenamine silver and Masson's trichrome [8]. at PENNSYLVANIA STATE UNIV on March 6, 2016vet.sagepub.comDownloaded fro