Serological survey of influenza type A viruses in dogs living in poultry farms in North-eastern Italy

Our study reports on a serological survey for antibodies to influenza type A viruses in dogs living in areas at high risk of introduction and spread of influenza viruses in North-eastern Italy, where LPAI and HPAI outbreaks have been frequently reported. The serosurvey was aimed to provide further information about the possibility of dogs of being infected and spreading of avian influenza viruses (AIV). In 2008 a total of 59 serum samples were collected from dogs kept as companion animals in 38 poultry farms located in the provinces of Padua and Rovigo (Veneto region). Ten farms had been affected by HPAI H7N1 outbreaks and 4 by LPAI H7N3 in 2000 and 2003, respectively. Furthermore, 7 canine sera were collected in a dealer farm (ornamental birds), where there was an ongoing outbreak of LPAI H7N3 in the birds. Screening of serum samples, using a Mab-based competitive ELISA detecting nucleoprotein A (NPA) of influenza viruses, showed that none was positive to anti-NPA antibodies. This finding seems to support the hypothesis that dogs are at very low risk of AIV infection and that their role into the natural transmission cycle of influenza viruses is very limited.