CONCLUSION

This study provides a comprehensive molecular epidemiological investigation of FPV and CPV infections among companion animals in Gujarat, India. The findings demonstrated widespread circulation of parvoviruses, with qPCR identifying a substantially higher prevalence (62.0%) than conventional PCR (19.5%) and RAT (5.0%), confirming the superior diagnostic sensitivity of probe-based qPCR. Molecular characterization based on the VP2 gene revealed that FPV isolates remained highly conserved, whereas CPV isolates exhibited greater genetic diversity, predominantly clustering with contemporary CPV-2c variants. Detection of CPV in feline samples and occasional detection of FPV in canine samples further indicated the potential for cross-species transmission, while successful virus isolation in CRFK cells confirmed the infectivity of circulating field strains.

From a practical perspective, the study highlights the importance of implementing highly sensitive molecular diagnostic methods, particularly qPCR, for routine diagnosis, surveillance, and differentiation of FPV and CPV infections. The predominance of CPV-2c-like variants and evidence of antigenic divergence from prototype and vaccine strains emphasize the need for continuous molecular surveillance and periodic evaluation of vaccine effectiveness. These findings also reinforce the importance of maintaining adequate vaccination coverage, strengthening biosecurity practices, and monitoring apparently healthy animals that may serve as asymptomatic carriers contributing to viral transmission.

A major strength of this study is the integration of epidemiological investigation, comparative evaluation of diagnostic methods, virus isolation, molecular characterization, and phylogenetic analysis within a single regional survey. Inclusion of both clinically affected and apparently healthy companion animals from diverse management systems provides a comprehensive overview of parvovirus circulation under field conditions.

Nevertheless, the study has certain limitations. Partial sequencing of the VP2 gene limited complete subtype characterization and assessment of all antigenically important mutations. In addition, the cross-sectional study design and reliance on descriptive statistics precluded detailed evaluation of epidemiological risk factors and temporal transmission dynamics.

Future investigations should incorporate whole-genome sequencing, longitudinal surveillance, larger multicenter sample collections, and advanced epidemiological analyses to better understand viral evolution, host adaptation, transmission pathways, and the emergence of novel variants. Continuous monitoring of circulating strains together with regular assessment of vaccine efficacy will be essential to ensure effective prevention and control of parvoviral infections.

In conclusion, the present study provides important baseline epidemiological and molecular evidence demonstrating the co-circulation of genetically distinct FPV and CPV strains in Gujarat, India. The predominance of CPV-2c-like variants, evidence of cross-species transmission, and superior performance of qPCR underscore the necessity for continuous molecular surveillance, sensitive diagnostic strategies, and optimized vaccination programs to improve the control of parvoviral infections in companion animal populations.