A Case of Newcastle disease from an outbreak in a commercial broiler farm in Mymensingh city, Bangladesh

Abstract

Background Newcastle disease (ND) is a contagious and often deadly viral disease caused by the Newcastle disease virus (NDV), affecting a wide variety of domestic and wild birds. The outbreak of this fatal disease is one of the greatest constraints to the expansion of poultry farms, resulting in significant financial losses. Here we report the clinical and pathological features of a ND case from an outbreak in a commercial broiler farm. Materials and Methods A broiler farm with a population of 850 birds aged 27 days reported the death of 100 chickens within 4 days of the onset of the disease in 2019. For investigation, one dead chicken was brought to the department of pathology, Bangladesh Agricultural University, Mymensingh. The case history was recorded, and an autopsy was performed. Portion of the samples were kept in 10% neutral buffered formalin for histopathological study. Results The morbidity and mortality rates were reported to be 17.65% and 11.47%, respectively. Recorded clinical history were depression, off-feed, huddling, gasping, ruffled feathers, greenish diarrhea, soiled vent and the birds were unvaccinated. On external examination, the birds appeared dehydrated, dyspneic and had nasal exudates, ruffled feathers, and soiled vents. Autopsy exhibited prominent gross lesions in the trachea, lungs, proventriculus, gizzard, intestine, cecal tonsil, liver, spleen and cloacal bursa. Grossly, tracheal hemorrhage, severe congestion in the lungs, pin point hemorrhages on the tip of the proventriculur glands, hemorrhage in the cecal tonsil, button-like ulceration in the intestine and mottled spleen were suggestive of ND. Histopathologically, severe enteritis, necrotic mass in the cecal tonsil and proventriculus, lymphoid depletion in the spleen supported the infection of NDV. The clinicopathological findings of the ND outbreak in broiler farm confirmed that it was velogenic viscerotropic in nature. Conclusion ND in commercial flocks remains a threat to the poultry industry in Bangladesh. Implementation of strict biosecurity, husbandry practice and effective vaccination are required to prevent diseases and improve economic stability.

Pathological and Epidemiological Study on Newcastle Disease in Broiler Chicken Farms in Egypt between 2021-2022.

“…Lentogenic strains had low mortality and few symptoms (Alexander, 2000). Grossly velogenic strains showed hemorrhage and necrosis in the proventriculus, cecal tonsils, and enlarged and mottled spleen with pinpoint focal areas of necrosis (Mostaree et al, 2021). Mesogenic strains have minimal gross lesions with severe morbidity observed in birds due to concurrent viral and secondary bacterial infections (Nakamura et al, 1994).…”