Prevalence of Gastrointestinal Parasites and Associated Risk Factors Among Dairy Cattle in Bangladesh: An 8-Year Retrospective Study.

BACKGROUND

Gastrointestinal (GI) parasitism remains a critical challenge in livestock health management, particularly in tropical regions where environmental conditions favor parasite proliferation. This study conducted an 8-year retrospective analysis (2017-2024) of GI parasites in dairy cattle across 11 districts in Bangladesh.

METHODS

Data were sourced from a private veterinary diagnostic laboratory, with a focus on the prevalence, types, and trends of GI parasites as well as associated risk factors. GI parasites were identified using different coproscopic methods including direct smear, flotation, and sedimentation. Statistical analysis was performed using descriptive analysis, followed by Poisson regression.

RESULTS

The most prevalent parasites identified were Schistosoma spp. (57.3%) and Paramphistomum spp. (22.6%), with notable peaks in prevalence during the years 2019 (65%) and 2021 (62%) for Schistosoma spp. and in 2017 (32%) for Paramphistomum spp. Other parasites, such as Balantidium (B.) coli, presented a lower but consistent prevalence (9.8%), whereas Fasciola spp. and Haemonchus spp. were identified less frequently. The analysis revealed that various factors significantly influenced parasite incidence, including seasonal variations, district-specific ecological conditions, and animal-related factors. Statistical analyses, particularly Poisson regression, demonstrated that male cattle (RR: 0.30, 95% CI: 0.230-0.401) had a lower risk of infection with Schistosoma spp. than females, whereas regions with abundant water bodies, such as Manikganj (RR: 11.9, 95% CI: 6.801-20.648, p < 0.001), Mymensingh (RR:7.9, 95% CI: 2.243-27.78, p < 0.01), and Narayanganj (RR: 6.6, 95% CI: 3.867-11.177, p < 0.001), presented higher prevalence rates. Seasonal trends revealed increased prevalence rates during the winter (Schistosoma spp.: RR: 1.5, CI: 1.090-1.919, p < 0.05; Paramphistomum spp.: RR: 1.03, 95% CI: 0.322-3.299; B. coli: RR: 1.2, 95% CI: 0.672-2.151; and Fasciola spp. RR: 2.5, 95% CI: 1.322-4.555), which aligns with periods of more significant water usage and potential exposure to contaminated sources.

CONCLUSION

This study underscores the need for targeted parasite control programs, particularly in high-risk areas, and advocates for improved livestock management practices and regular veterinary interventions to mitigate the economic and health impacts of GI parasites. These findings provide valuable insights for developing tailored parasite management strategies to increase the productivity and well-being of dairy cattle in Bangladesh.