CLINICAL, VIROLOGICAL AND MOLECULAR CHARACTERIZATION OF CANINE PARVO VIRUS IN DOGS

Rofaida M. Soliman*, Nabil M. Baker, Mohamed Y. Nasr and Mohamed H. Khodeir

ABSTRACT

Canine parvovirus (CPV-2) remains the most important and potentially fatal viral disease seen in canine populations especially young pups causing acute hemorrhagic enteritis and myocarditis. Based on this, the present study aimed to investigate the different methods for diagnosis of CPV-2 infection, detection and genotyping of CPV-2 circulating in Egypt by polymerase chain reaction (PCR). A total of 50 fecal samples were collected from diarrheic dogs suspected to be infected with CPV-2 based on clinical findings. All the cases were screened for CPV-2 using immunochromatographic (IC) test, out of which 25 (50%) were positive while 25 (50%) were negative. 18 samples were chosen randomly (8 positive by rapid test kit and 10 negative) plus the local vaccine for PCR. It was found that all 18 samples (in addition to the local vaccine) were found clearly positive for parvoviruses by PCR assay using Hfor/Hrev primers. Two positive samples plus the vaccine were subjected to further genotyping. The three samples were positive CPV2b indicating that this CPV type 2b is the currently circulating genotype in Egypt. Virus isolation and identification were made to demonstrate the cytopathic effects of the virus. Phylogenetic tree revealed that CPV-2b VP2 partial sequences were phylogenetically associated with one of the most commonly used CPV vaccine strains (Fort-dodge vaccine). This study revealed that PCR is considered as the most reliable diagnostic technique having high degree of sensitivity and specificity in detecting CPV-2 from fecal samples, helping in identification of dogs shedding CPV-2 at low titers in their feces.

Keywords: CPV-2, dogs, hemorrhagic enteritis, diagnosis, immunochromatographic (IC) test, PCR.