Prevalence and molecular characterization of parvoviruses in dogs and domestic cats in Guangxi, China: new emergence of CPV-2c in cats

Abstract

Feline panleukopenia virus (FPV) and its canine-adapted derivative, canine parvovirus (CPV), cause severe gastroenteritis in their respective hosts. To investigate the molecular epidemiology and cross-species transmission of these viruses, we conducted a large-scale surveillance study in Guangxi, China. From 1257 fecal samples from dogs (n = 552) and domestic cats (n = 705), we obtained 86 VP2 gene sequences. Phylogenetic analysis revealed three CPV subtypes circulating in dogs: New-CPV-2a (5.3 %, 3/57), New-CPV-2b (1.8 %, 1/57), and the predominant CPV-2c (93.0 %, 53/57), all clustering with contemporary Asian strains. These variants exhibited 17 amino acid substitutions in the VP2 capsid protein, including key residues associated with host adaptation and antigenic variation. Crucially, we detected five CPV-2c strains in domestic cats that contained the S564N and G568A mutations in VP2-residues previously implicated in feline host adaptation. While FPV-G3 (79.2 %) remained predominant in cats, the emergence of CPV-2c in felines demonstrates active cross-species transmission. Our study demonstrates the complex molecular epidemiology of parvoviruses in southern China and documents the expanding host range of CPV-2c. These findings underscore the need for continuous surveillance using whole-genome sequencing to track viral evolution and inform vaccine development.