Canine Adenoviruses in Wildlife: Role in At-Risk Species Conservation and Interface with Domestic Animals

Canine adenovirus type 1 (CAdV-1) and type 2 (CAdV-2) are well known pathogens of domestic dogs but are little investigated in wild animals. The few available studies about CAdV-1 in wild animals show that it circulates in various species and that transmission of the virus in the interface between wildlife and domestic animals is a frequent event. Furthermore, wild animals are usually subject to asymptomatic infections, but cases of serious and fatal diseases have been documented, with possible effects on the conservation of the species. In contrast, CAdV-2 infection was reported only recently and sporadically in some wild animals, with few data regarding its pathogenic role in these species. However, the real prevalence of these viruses in wildlife is still uncertain due to the use of serological tests that are largely unable to distinguish antibodies against CAdV-1 and CAdV-2. This review, reporting all the data currently available on CAdV-1 and CAdV-2 infection in wild animals, highlights the importance of these pathogens for wildlife conservation and their role in the potential transmission of the infection to domestic dogs.