Cerebral vasculitis in pigs: pathological and serological investigations

Vasculitis are inflammatory lesions affecting blood vessels associated with direct infections of vessel wall or with immunologic mechanism not directly caused by the pathogens.214 brains collected from regularly slaugthered Nebrodi feral Black pigs aged from 6 to 24 months were submitted to anatomo-histopathological investigations. Immunohistochemical studies were performed to characterize the inflammatory cells and to detect the presence of Aujeszky virus infection. Serological texts were performed for detection of antibodies against Leptospira spp., Mycoplasma spp., Salmonella spp., Toxoplasma gondii, Neospora caninum, Aujeszky virus, PCV2, PRRS, Influenza virus, tick-borne encephalitis virus (TBEV), Coronavirus and Parvovirus. 48% of the animals showed pathological lesions. The main lesions were inflammations (76.06%) and precisely diffuse encephalitis (10.32%), leptomeningitis (28.57%), multifocal or focal mononuclear perivascular cuffs (29.37%), arteritis (23.80%) and plexus choroiditis (7.94%). The most significant findings were arteritis classified as periarteritis nodosa. The affected arteries were distributed expecially in cerebral meninges and less frequently in other areas of the cerebral cortex and in basal nuclei area. The arteritis were characterized by fibrinous necrosis and severe infiltrates mainly composed by lymphocytes and monocytes. Malacic areas were observed also in three brains sometimes associated to periarteritis. Immunohistochemistry for Aujeszky was negative in all samples. Periarteritis nodosa are reported in many species and seem to be an immune complex disease. In swine viral or Streptococcal infections are considered the possible causes of these lesions. Further investigations are in progress in order to better understand the aetiopathogenesis of these vasculitis