A common agama (Agama agama) with clinical signs of dehydration, anorexia, and an abscess in the oral cavity was presented for medical examination. Bacteriological testing of an oral swab demonstrated the presence of Proteus vulgaris and Morganella morganii (Proteus morganii). A fecal examination showed oocysts of Choleoeimeria sp. and pinworm eggs. The animal died four days after examination. Samples from organs (liver, kidney, heart, and intestine) were collected for virological testing. An adenovirus was detected by polymerase chain reaction testing in the intestine. Analyses of the partial DNA-dependent–DNA-polymerase gene sequence of this adenovirus showed that the detected adenovirus clustered with members of the genus Atadenovirus.