Among the diseases that affect equines, viral diseases play an important role from a health and economic point of view, especially influenza, viral arteritis, herpes infections and vesicular stomatitis. In the Brazilian literature, there is little or no account of the occurrence of infectious diseases in donkeys. Given the importance of donkeys in different activities and the lack of information on infections that may occur in these animals, the aim of this study was to determine the frequency of anti-equine herpesvirus (EHV), anti-equine arteritis virus (EAV), anti-vesicular stomatitis, and anti-equine influenza (H3N8) antibodies in the serum of 85 donkeys bred in some regions of the state of Sao Paulo. We found the following antibody frequencies: 50.6% (43/85) antibodies against influenza virus subtype H3N8, 47% (40/85) anti-EHV, and 20% (17/85) anti-EAV. The donkeys were not seropositive for vesicular stomatitis. The results suggested that the agents EHV, EAV, and equine influenza subtype H3N8 circulate among donkeys in some regions of the state of Sao Paulo, Brazil, reinforcing the importance of establishing a routine diagnosis and epidemiological study of this species.