Abstract
Despite the significant growth in Sonali chicken production across Bangladesh, inadequate disease surveillance and control measures along with indiscriminate antimicrobial use remain major challenges to the sector. In this study, we evaluated the disease burden and antimicrobial prescription patterns of Sonali chickens in Bangladesh using a web-based data recording system from 2020 to 2021 and analyzed 1690 cases. The diagnoses recorded in the system were presumptive, as they were based on clinico-epidemiological history, clinical signs, and gross necropsy findings noted by registered veterinarians. We conducted this study in Bogura, a district renowned for its high concentration of Sonali chicken farms. We estimated a higher prevalence of infection among grower chickens (69.0%) compared to starter chickens (31.0%). Small- to medium-sized flocks (63%) were more frequently infected than larger flocks (37.0%). Most disease cases occurred during the summer season (43.0%), followed by winter (27%), the rainy season (15%), and autumn (14%). Overall, climatic factors contributed to 51% of disease occurrence at temperatures below 25°C, 55% at high humidity (≥75%), and 57% during heavy rainfall (≥29 mm). The most prevalent disease was Newcastle disease (ND) (19.5%), followed by Marek's disease (9.8%), coccidiosis (7.4%), necrotic enteritis (4.7%), infectious bursal disease (3.2%), and infectious laryngotracheitis (3.2%). The odds of ND were 1.4 (grower chickens vs. starter chickens), 11.4 (summer vs. winter), 4.1 (autumn vs. winter), 3.9 (rainy vs. winter), 3.5 (≥25 °C vs. <25 °C), and 2.6 (≥75% vs. <75%). Tylvalosin (38.0%) was the most frequently prescribed antibiotic, followed by fluoroquinolones (9.0%), aminoglycosides (8.0%), and colistin sulphate (4.0%). These findings suggest that a web-based disease record could be an important tool for a centralized poultry disease surveillance system in low- and middle-income countries like Bangladesh.