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Novel goose parvovirus (NGPV) is continuously threatening the global duck industry, as it causes short beak and dwarfism syndrome among different duck breeds. In this study, we investigated the viral pathogenesis in the tongue of affected ducks, as a new approach for deeper understanding of the syndrome. Seventy-three, 14- to 60-day-old commercial Pekin ducks were clinically examined. Thirty tissue pools of intestine and tongue (15 per tissue) were submitted for molecular identification. Clinical signs in the examined ducks were suggestive of parvovirus infection. All examined ducks had short beaks. Necrotic, swollen, and congested protruding tongues were recorded in adult ducks (37/73, 51%). Tongue protrusion without any marked congestion or swelling was observed in 20-day-old ducklings (13/73, 18%), and no tongue protrusion was observed in 15-day-old ducklings (23/73, 32%). Microscopically, the protruding tongues of adult ducks showed necrosis of the superficial epithelial layer with vacuolar degeneration. Glossitis was present in the nonprotruding tongues of young ducks, which was characterized by multifocal lymphoplasmacytic aggregates and edema in the propria submucosa. Immunohistochemical examination displayed parvovirus immunolabeling, mainly in the tongue propria submucosa. Based on polymerase chain reaction, goose parvovirus was detected in 9 out of 15 tongue sample pools (60%). Next-generation sequencing confirmed the presence of a variant goose parvovirus that is globally named NGPV and closely related to Chinese NGPV isolates. Novel insights are being gained from the study of NGPV pathogenesis in the tongue based on molecular and immunohistochemical identification. [ABSTRACT FROM AUTHOR]

New castle disease virus affecting poultry industry resulting in extensive chicken mortalities and economic losses. Evaluation of distribution and severity of neuropathological lesions progressed in different areas of central nervous system was performed in chickens experimentally infected by velogenic Newcastle virus (vNDV). Chickens were inoculated by genotype VII strain (NDV-B7-RLQP-CH-EG-12) via intraocular route at different ages (10, 20 and 30 days old). Serum samples for antibody titer estimation and tissue sections from nervous system were collected for histopathological examination at 1, 3, 5 and 7-days post inoculation (dpi) from all groups. Results indicated that there was variation in antibody titers among different age groups. Encephalitis, myelitis with marked demyelination and axonal spheroids formation were the main neuropathological alterations. Lesions were detected in different areas of central nervous system which vary in distribution and severity among age and duration of infection with complete tract degeneration which was responsible for the developed nervous signs. The experimental infection of broilers by vNDV via intraocular inoculation induced virus dissemination into the central nervous system with progression of neuropathological lesions that were varied in severity, distribution and the onset according to the age of birds with subsequent development of nervous clinical signs and mortalities, in addition the distribution of virus along the CNS clarify the possible pathways of virus dissemination and progression in the neuroparenchyma denoting the neuropathogenesis of the vNDV. The age of bird at the time of infection is a crucial factor in determining the viral replication in neuroparenchyma with subsequently developed neuropathology. [ABSTRACT FROM AUTHOR]

In this study, we investigated the pathological effect of novel goose parvovirus (NGPV) infection on the skeletal muscle, brain, and intestine of naturally affected ducks suffering from locomotor dysfunction as a new approach for deeper understanding of such clinical form. For this purpose, a total of 97 diseased ducks, representing 24 flocks of different duck breeds (14-75 days old), were clinically examined. 72 tissue pools of intestine, brain, and skeletal muscle samples were submitted for molecular identification. Typical clinical signs among the examined ducks suggested the parvovirus infection. Regarding postmortem examination, all examined ducks showed muscle emaciation (100%) either accompanied by congestion (34%) or paleness (66%). Slight congestion, either in the brain (82.5%) or intestine (75.25%), was predominantly detected. Based on molecular identification, the intestine had the highest percentage of positive detection (91.7%), followed by the skeletal muscle (70.8%), and the brain (20.8%). The main histopathological alterations were myofiber atrophy and degeneration, marked enteritis accompanied by lymphocytic infiltration in the lamina propria and submucosa, while the affected brains showed vasculitis, diffuse gliosis, and Purkinje cell degeneration in the cerebellum. Next generation sequencing further confirmed the presence of a variant strain of goose parvovirus (vGPV) that is globally known as NGPV and closely related to Chinese NGPV isolates. Using immunohistochemistry, the NGPV antigen was positively detected in the muscle fibres, enterocytes, and Purkinje cells in the cerebellum. These findings provided proof of the involvement of virus replication in the locomotor disorders linked to NGPV infection in ducks. [ABSTRACT FROM AUTHOR]