2.4 Recombination analysis
In order to find potential natural genetic recombination events in the evolution of the Vietnamese CPV-2 strains, the dataset of CPV-2 genomes used in the evolutionary analysis (section 2.3) were further subjected to recombination analysis using various statistical methods, including recombination detection program (RDP), GENECONV, BootScan, MaxChi, Chimaera, SiScan, and 3Seq with the default settings in the RDP package version 4.0 (Piewbang et al., 2018). Because many recombination signals would be detected during the test run and the different algorithms might be inconsistent, then the acceptance criteria of any potential breakpoint signal must be revealed by at least four methods withp -values < 0.01 was applied to recognize any potentially positive recombination event.