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Twenty-two feral rock pigeons ( Columba livia) from 10 counties in California with ataxia, torticollis, and difficulty standing and flying were admitted to rehabilitation centers in late winter and spring of 2017 and died or were euthanized. Common necropsy findings included thin body condition, generalized deep red discoloration of organs, and hemorrhagic subcutaneous neck tissues. Meningoencephalitis was observed microscopically in 16 pigeons, and 3 also had protozoal schizonts in the brain. The most consistently affected regions of the brain were cerebellum and brainstem. Skeletal muscles, and less frequently the heart, contained large intrasarcoplasmic bradyzoites typically without inflammation. Fifteen of the 22 birds tested positive using pan- Sarcocystis polymerase chain reaction. The sequence of the amplicon was most closely related to S. calchasi, and the 8 subtyped sequences had 100% homology with S. calchasi. This investigation demonstrated the transcontinental and North American spread of S. calchasi causing a disease outbreak in free-ranging rock pigeons, thus warranting increased surveillance in susceptible native columbids.

Reports of primary nervous system tumors in wild raccoons are extremely rare. Olfactory tumors were diagnosed postmortem in 9 free-ranging raccoons from 4 contiguous counties in California and 1 raccoon from Oregon within a 26-month period between 2010 and 2012. We describe the geographic and temporal features of these 10 cases, including the laboratory diagnostic investigations and the neuropathologic, immunohistochemical, and ultrastructural characteristics of these tumors in the affected animals. All 9 raccoons from California were found within a localized geographic region of the San Francisco Bay Area (within a 44.13-km radius). The tight temporal and geographic clustering and consistent anatomic location in the olfactory system of tumor types not previously described in raccoons (malignant peripheral nerve sheath tumors and undifferentiated sarcomas) strongly suggest either a common cause or a precipitating factor leading to induction or potentiation of neuro-oncogenesis and so prompted an extensive diagnostic investigation to explore possible oncogenic infectious and/or toxic causes. By a consensus polymerase chain reaction strategy, a novel, recently reported polyomavirus called raccoon polyomavirus was identified in all 10 tumors but not in the normal brain tissue from the affected animals, suggesting that the virus might play a role in neuro-oncogenesis. In addition, expression of the viral protein T antigen was detected in all tumors containing the viral sequences. We discuss the potential role of raccoon polyomavirus as an oncogenic virus., (© The Author(s) 2013.)