Newcastle disease (ND) is a highly contagious viral disease caused by the paramyxovirus, which is a single-stranded ribonucleic acid (RNA) virus. This study was conducted to investigate ND outbreaks in 10 vaccinated or non-vaccinated broiler farms, collectively housing 9840 birds of various ages in the Chitwan and Nawalpur districts of Nepal from July to December 2021. Clinically, the affected birds exhibited symptoms such as limb paralysis, greenish diarrhea (seven out of ten flocks), torticollis (two out of ten flocks), inappetence, and drowsiness (ten out of ten flocks). Birds that succumbed during the clinical course underwent a necropsy for gross pathology and samples were collected for the histopathology and molecular diagnosis. The gross and microscopic examination revealed hemorrhages in the proventriculus, erosions and ulcers in the small intestine, congestion, as well as sero-mucosal hemorrhages in the trachea of affected birds, which are typical of ND. Rapid test kits further confirmed the presence of the ND virus antigen while excluding the avian influenza virus. Furthermore, M gene-based real time polymerase chain reaction (RT-PCR) was performed in the pooled samples from the affected birds and the presence of a velogenic strain of the ND virus was identified. The phylogenetic analysis of the RT-PCR positive strain based on the partial F gene nucleotide sequence revealed these strains as genotype VII.2 (formerly VIIi). The findings highlight the occurrence of clinical ND outbreaks in farms despite adherence to recommended vaccination protocols in broiler flocks, underscoring the need for a regular comprehensive investigation involving in-depth examinations of available vaccines and genetic analyses.

Background and Aim: Kathmandu is a densely populated metropolitan city in Nepal. In recent years, however, the metropolis has been ranked as one of the most polluted cities worldwide. Both humans and animals are susceptible to various respiratory diseases due to chronic exposure to polluted air. Due to the relative similarities in the anatomical structure and physiological functions of the respiratory system between humans and dogs, polluted environments may lead to respiratory illness in similar ways in both species living in the valley. On the basis of information on the air quality in the valley, this study was conceived to assess pulmonary illness in street dogs to discern the health hazards caused by polluted air. Materials and Methods: A total of 76 dogs with clinical signs of tachypnea, dyspnea, sneezing, coughing, mucopurulent discharge, moderate hyperthermia, and anorexia admitted from July 2020 to November 2020 in Animal Nepal for treatment were included in this study. Among them, 24 animals responded to treatment, and 52 dogs died during their stay in the hospital. The 52 dead animals were necropsied, and the lesions that resembled pulmonary anthracosis were further studied grossly and histologically in a blinded fashion by trained veterinary pathologists. Results: Significant morphological alterations were observed in the lungs and associated lymph nodes of 25 animals, indicating pulmonary anthracosis. Gross morphological changes included multiple black foci with hemorrhage, congestion, nodular, and emphysema on the parietal and visceral surfaces of the lungs. The alveolar septa and visceral pleura exhibited deposition of black particles. Congestion, emphysema, and inflammatory exudates were also detected in the lung tissues and lymph nodes. Conclusion: The clinical, gross, and microscopic findings accurately resembled those of pulmonary anthracosis. This life-threatening condition in stray canines may be caused by a critical level of air pollution from different sources and carbon emissions from vehicles. To protect animals and humans living in the Kathmandu Valley, concerned government and non-government agencies should work toward reducing air pollution levels as soon as possible. Keywords: air pollution, histopathology, Kathmandu, pulmonary anthracosis, respiratory disease, stray dogs.