Epidemiological aspects of Aujeszky's disease in Austria by the means of six cases in dogs Introduction and clinical data Aujeszky's disease, primarily a pathogen for swine, may infect domestic animals and is caused by the Suid Herpesvirus-1. Oral ingestion of tissue or bite from infected wild boar is suspected to be of epidemiological importance for dogs. From 2008-2010, six dogs developed clinical symptoms within three to five days after hunting wild boar, where contact to the shot boars was suspected or even observed. Clinical symptoms in all six dogs included pruritus, salivation and rapidly progressive neurological symptoms leading to coma and death within 16-44 hours. Necropsy was performed in all six dogs. Material and methods After necropsy, histological sections of the brain and other organs were stained with haematoxilin and eosin. Immunohistochemical staining for SuHV-1 was performed from frozen and paraffin embedded brain samples. For confirmation of Aujeszky's disease, gB-PCR and sequencing was performed. Cerebrospinal fluid (CSF) samples were examined for cell count and total protein in four dogs. Results The pathohistological examination revealed a nonpurulent, sometimes side accentuated, encephalitis of the brain stem with intranuclear inclusion bodies in six dogs. Immunohistochemical examination demonstrated SuHV-1 antigen, and gB-PCR and sequencing confirmed Aujeszky's disease. Only one CSF sample revealed signs of inflammation. Discussion Regarding domestic swine, Austria has been declared free of Aujeszky's diseases in 1997. In conclusion, infection of the six hunting dogs is suspected to be caused by direct contact to infected wild boar carcasses. Epidemiological influence of possibly infected wild boar in Austria on the Austrian swine population as well as safety measures to provide infection in hunting dogs are discussed.