Introduction: Newcastle disease (ND) is one of the major causes of economic and production losses in poultry industry. There are only few reports of the ND in wild birds. In this paper we report a case of vvND in a migratory wild bird, in Iran’s Northeastern Town of Quchan. Material and Method: A dead Great Crested Grebe (Podiceps cristatus) with the history of nervous signs, depression and green diarrhea referred to Maad Professional poultry Hospital. Clinical observation and postmortem examination were performed. For virus isolation samples were taken, homogenized and inoculated in embryonated eggs. The allantoic fluids were examined by HA and HI assays. RNA was extracted and RT-PCR assay performed using specific primers amplifying the cleavage site. The PCR products were sequenced, edited, analyzed and phylogenetic tree was drawn. Results, Discussion and Conclusion: In necropsy moderate hemorrhage of the mucosa of the proventriculus, intestinal tract and cecal tonsils were found. The alantoic fluids were positive in HA and HI assays. RT-PCR assay and sequencing confirmed identity of the isolate as vvNDV. Analysis of the deduced amino acid sequence showed the amino acid sequence 111-GRRQKRF-117 in F0 cleavage site, specific for velogenic strains. The phylogenetic analysis revealed that the virus belong to Class II, genotype VIId. This investigation may indicate the circulation of vvNDV in wild migratory birds, although the possibility of infection through contact with infected poultry farms cannot be ruled out. The current outbreaks of vvND observed in different countries located in corridor path of migratory birds may also indicate the impact of migratory fowls in distribution of the virus across countries. The first report and evidence of NDV in wild waterfowls is dated back to 1957 in USA. NDV has been detected in many species of birds. Although it is known that all of 8000 species of birds are susceptible to NDV infection, but in practice it is also believed wild bird species are the natural reservoir of the virus and are resistant to ND. Most virus isolates from wild birds, so far were belonged to lentogen strains. To our knowledge, this is the first report of velogenic viscerotropic Newcastle disease in a migratory waterfowl, Great Crested Grebe (Podiceps cristatus) in Iran. This report is also among a few rare reports of vvND in wild waterfowl population. It is recommended to monitor the presence and prevalence of vvNDV, along with avian influenza virus subtypes in wild migratory waterfowls.

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