Diagnosis and serological study of canine parvovirus infection in dogs from Passo Fundo, Rio Grande do Sul, Brazil

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">The polymerase chain reaction (PCR) and hemaglutination (HA) assay were used to detect canine parvovirus (CPV) in feces from young dogs with gastroenteritis. The hemaglutination inhibition (HI) assay was used to detect the prevalence of anti-CPV antibodies in a non-vaccinated dog population. In addition, hiperimmune serum was used to investigate the phenotypic variability of a vaccine strain and two field isolates of CPV. Thirty fecal samples obtained from dogs with diarrhea were submitted to PCR and HA, and 185 serum samples were submitted to HI to detect anti-CPV antibodies. Nine (30%) of the samples demonstrated HA on fecal dilutions equal to or above 1:64 and were considered positive by this test; nine (30%) fecal samples had HA activity on dilution from 1:2 to 1:32 and were considered negative, and the remaining samples were negative. All samples with HA activity at dilutions above 1:64 were also positive to PCR and, out of the nine samples with HA activity at dilutions between 1:2 and 1:32, six were also positive by PCR. Serological analysis of the dog serum samples indicated that 178 (96,2%) of the dogs had previous contact with the virus. Hiperimmune serum indicated possible phenotypic differences among isolates, in that different HI titers were obtained following cross-HI assay.