Goose parvovirus (GPV) causes acute enteritis, hepatitis, myocarditis and high morbidity and mortality in geese and ducks. GPV H strain was isolated from a Heilongjiang goose farm where the geese were showing signs of hemorrhage in the brain, liver, and intestinal tract. In this study, we explored the genetic diversity among waterfowl parvovirus isolates and the pathological characteristics of GPV H in Shaoxing ducklings. The complete capsid protein (VP) and non-structural (NS) sequences of the isolated H strain were sequenced, and phylogenetic trees of VP and NS were constructed in MEGA version 5.05 using the neighbor-joining method. Three-day-old Shaoxing ducklings were inoculated with GPV and were euthanized at 1, 2, 4, 6, and 8 days post-inoculation (PI), and their organs were removed and collected. The organs of 6-day PI ducklings were fixed in formalin, embedded in paraffin, sectioned for histology, stained with HE and analyzed for pathological lesions. The distribution of the GPV H strain in the tissues of the inoculated ducklings was detected using the polymerase chain reaction (PCR) method. Genetic analysis of the NS and VP genes indicated that the H strain was closely related to strains circulating in China during 1999–2014, and the nucleic acid identity of those strains was 98%–99%. Classical symptoms were observed in the inoculated ducklings. GPV remained in many tissues and replicated in a majority of the tissues, leading to histopathological lesions in four tissues. We first reported the distribution and histopathological lesions of a Chinese strain of GPV in infected shaoxing ducklings. This H strain was moderate pathogenic for Shaoxing ducklings.

Mink circovirus (MiCV) is a newly discovered pathogen associated with mink diarrhea. The prevalence and economic importance of this virus remain poorly understood, and no specific serological assay has been developed for the diagnosis of MiCV infection. In this study, a recombinant capsid protein antigen expressed in Escherichia coli was utilized to establish an indirect enzyme-linked immunosorbent assay (iELISA). Results revealed that the assay had no cross-reactivity with other related pathogens, and the respective sensitivity and specificity of the proposed iELISA were 92.31% and 91.67% compared with those obtained of Western blot on 138 serum samples from minks. The correlation coefficient between iELISA and Western blot was 0.838 (p > 0.05). iELISA was applied to detect MiCV antibodies in 683 clinical serum samples from different farms from the major mink industry province in China, and 21 of 24 farms with 163 of 683 (23.87%) individuals were tested positive for MiCV antibodies. The positive rates of each of the 21 flocks ranged from 2.33% to 73.68%. These results indicated that iELISA was a sensitive and specific method suitable for the large-scale detection of MiCV infections in mink. This study provided an effective method for the serological diagnosis and positive rate investigation of MiCV infection.