The genus "Mastadenovirus" comprises viruses of the family Adenoviridae, which occur exclusively in mammals. The name of the genus is also derived from this characteristic (Greek mastos = female breast). Mastadenoviruses have so far been found in cattle, horses, sheep, goats and pigs, as well as in rodents. Mastadenoviruses have also been found in humans and closely related great apes (see human adenoviruses). Mastadenoviruses most commonly cause infections of the respiratory tract, ocular conjunctiva, and urinary bladder.
The genus mastadenovirus comprises 7 human pathogenic subgroups (A-F) with 47 serotypes.