Clinical and pathological characterization of a novel canine parvovirus type 2c variant in dogs in Viet Nam

Abstract

Canine parvovirus type 2 (CPV-2) is a highly contagious pathogen causing fatal enteric and myocardial diseases in domestic dogs in the worldwide. CPV-2 exhibits genetic variations, with different genotypes emerging over time. In recent years, a new CPV-2c variant named "new-var" has become popularly in Viet
Nam. Despite its prevalence, a comprehensive survey of the variant's prevalence and clinical-pathological characteristics is lacking. This study investigated the clinical and pathological features of the emerging CPV-2 "new-var" in Viet Nam. The studied result showed that there were 43 cases positive with the canine
parvovirus type 2c (CPV-2c) variant. The clinical manifestations of dogs with CPV-2c disease included lethargy, vomiting, loss of appetite, fever, especially bloody diarrhea, accounting for 60.47% of the total cases in this study. The result of autopsy revealed that there were the severe gastrointestinal and systemic lesions,
suggesting that more impactful disease manifestations compared to previous CPV-2c strains. Histological lesions were concentrated mainly in the digestive tract, such as congestion, hemorrhage in the stomach and mesenteric lymph nodes, necrotic intestinal epithelial cells, and broken villi. 9/9 organs of dogs in the study were positive with CPV-2c antigen by immunohistochemistry method. These findings underscore the dynamic evolution of CPV-2 strains and emphasize the importance of continuous surveillance to address emerging viral variants and optimize disease management strategies.