A study was conducted to characterise the field isolates of canine parvovirus (CPV) and an in vitro cross neutralisation assay was performed against the vaccinated dog sera. Out of 45 faecal samples processed for virus isolation, 27 samples showed cytopathic effect (CPE) at first passage, which were confirmed positive by CPV variant types specific PCR. The CPV type 2 was not detected in any of the clinical samples. Of these 27 positive samples only 23 samples showed CPE and were further confirmed as CPV by haemagglutination inhibition test, ELISA and immuno-chromatographic strip test. Antigenic typing performed using a panel of monoclonal antibodies revealed that four of the 23 isolates were CPV 2b type and the remaining 19 isolates were typed as CPV 2a. The antigenic typing results obtained using the monoclonal antibodies corroborated the sequencing results reported by our group earlier. The cross neutralization study with polyclonal sera revealed that the sera of original antigenic type CPV 2 can neutralize the antigenic variants 2a and 2b effectively. Thus we conclude that the vaccines containing CPV type 2 virus can be used to immunise the dogs against the prevalent CPV 2a and CPV 2b infection. A live virus challenge study in dogs may further confirm this observation
