Study on the Canine Adenovirus Type 1 (CAdV-1) Infection in Domestic Dogs in Southern Italy

Abstract

Canine adenovirus type 1 (CAdV-1) is the causative agent of a systemic and potentially fatal viral disease of domestic and wild canids. In Italy, CAdV-1 infection has also been occasionally described in dogs, but information on the epidemiology and its genomic features is still limited. A study was conducted on 291 dogs suspected of infectious gastrointestinal disease. Samples collected from dogs in southern Italy between 2017 and 2020 were analyzed. Virological and histopathological assays were carried out. The presence of CAdVs and other canine viral enteropathogens was investigated, and sequence and phylogenetic analyses were performed. CAdV-1 was detected in six (2.1%) dead stray dogs alone or in mixed infections with other viruses. Gross lesions and histopathological findings referred to CAdV infection were observed, also involving the central nervous system tissues. All inoculated samples were successfully isolated. Sequence analysis evidenced divergences with the circulating strains previously described in Italy and a closer relation with older CAdV-1 strains collected from other countries, suggesting a genetic heterogeneity of CAdV-1 in Italy. The evidence of the circulation of CAdV-1 and its genomic features allows us to have more in-depth knowledge of the epidemiology and evolution of the CAdV-1 genomic variants.

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

“…They reported that 2.1% of the total dogs were infected with CAdV‐1, either alone or co‐infected with other viruses (CPV‐2/CCoV). Additionally, the dogs that tested positive for CAdV‐1 were all dead stray dogs 24 . Also, in a study conducted in Turkey, Bulut et al.…”

“…After the introduction of CAdV-1 vaccines, ICH largely disappeared, but over the past decade, disease has re-emerged in Italy, Switzerland and the United States. 9,19,22,23 Co-infection by CAdV-1 and CCoV 22,24 or canine parvovirus 10,24 has been reported in dogs. A study was conducted in 291 dogs in southern Italy between 2017 and 2020, on the prevalence of canine gastrointestinal pathogens of viral origin.…”

“…Additionally, the dogs that tested positive for CAdV-1 were all dead stray dogs. 24 Also, in a study conducted in Turkey, Bulut et al determined the correlation between age and antibody prevalence in dogs presented with clinical signs of CAdV infection. The prevalence was higher among adult dogs aged 2 years and over.…”

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Dogs

“…Furthermore, the high CAdV-1 rates obtained in this study may be explained by the remarkable resistance in the environment of this virus that, similar to CPV-2, can act as natural booster in dogs that come into contact with it. CAdV-1 infection has occasionally been described in Italy both in wild animals and in dogs [ 24 , 31 , 58 , 59 , 60 ], as elsewhere. In addition, vaccines for infectious canine hepatitis contain CAdV-2 (and not CAdV-1) that, together with Bordetella bronchiseptica and parainfluenza viruses, is one of the major agents of the Canine Infectious Respiratory Disease Complex (CIRDC, formerly known as kennel cough or canine infectious tracheobronchitis).…”

“…The infection mainly affects dogs and other carnivores and damages the kidneys, liver, and eyes. Since the middle of the last century, its incidence in the canine population has been drastically reduced worldwide, thanks to systematic vaccination [ 17 , 22 , 23 , 24 , 25 ].…”