Detection and molecular characterisation of canine adenovirus type 1 from a fatal case of infectious canine hepatitis from India

Canine adenovirus (CAdV), a non-enveloped, linear dsDNA virus, is a member of the genus Mastadenovirus of the family Adenoviridae. Two different serotypes of CAdVs, canine adenovirus type 1 (CAdV-1), which causes infectious canine hepatitis (ICH), and canine adenovirus type 2 (CAdV-2), which causes canine infectious laryngotracheitis, have been identified in dogs. In this report, we discuss a case of fatal CAdV-1 infection in a 4-month-old, male, unvaccinated, Rajapalayam breed dog. Postmortem examination results were suggestive of CAdV-1 infection, which was confirmed by histopathological examination, molecular characterisation and phylogenetic analysis. Sequence analysis of the CAdV-1 strain showed a close similarity with the Australasian-Europe cluster, a high identity (99.78% nucleotide and 98.91% amino acid identities) with a CAdV-1 isolate (KU75571) from a fox in the United Kingdom, and a unique substitution (W126S) in the E3 protein encoding sequence.