EN
The infection of dogs with distemper virus (CDV), adenovirus type 1 (CAV-1) and parvovirus (CPV) is still being diagnosed by practitioners, even in vaccinated dogs. Laboratory techniques used for the isolation and identification of these viruses are usually time consuming and often their accuracy is not satisfactory. The presented studies concentrated on the adaptation of PLA (Peroxidase Linked Assay) for the evaluation of CDV, CAV-1 and CPV replication in tissue cultures. Comparable studies on titration of viruses tested on the basis of cytopathic effects and results of PLA revealed that the titre of CDV and CPV evaluated by CPE was lower than calculated using PLA. The difference was equal to 0.6 log for CDV and 0.7 log CPV. These results confirm four to five-fold higher sensitivity of PLA. Titre of adenovirus type 1 measured by both methods did not demonstrate significant differences which can be explained by production of regular and characteristic CPE and rapid spread of cell destruction. Results of PLA revealed that the expression of viral antigens takes place between 18 and 24 hours after cell inoculation, whereas the first cytopathic effect was visible after 48-96 hours. The repeatability of results obtained by PLA was significantly higher with p<0.05 than titration of viruses on the bases of CPE in the case of CAV-1 and CDV. The presented results confirm the high sensitivity and specificity of PLA, which could be widely used in studies on CDV, CAV-1 and CPV.