Bovine Mastitis in Bangladesh: Epidemiology, Etiology, Diagnosis, Antimicrobial Resistance and Sustainable Management Strategies

Abstract

Bovine mastitis is a major health, welfare, milk-quality, and economic constraint on dairy production in Bangladesh. It occurs as clinical mastitis, characterized by visible udder or milk abnormalities, and as subclinical mastitis (SCM), which causes inflammation and loss of production without obvious signs. Bangladesh studies report widely varying cow-level SCM prevalence, generally 20-60%, reflecting differences in production systems, regions, breeds, seasons, management, sampling, diagnostic tests, somatic cell count thresholds, and case definitions. Recent large-herd evidence found similarly high SCM prevalence in extensive and intensive systems, while yield and economic losses were greater during non-bathan confinement. Frequently reported risk factors include crossbreeding or high milk yield, increasing parity, late lactation, previous mastitis, poor body condition, udder or teat lesions, contaminated floors, inadequate drainage, unhygienic hand milking, common towels, failure to dry teats, absence of post-milking teat disinfection, and limited farmer awareness. Major pathogens include Staphylococcus aureus, non-aureus staphylococci, Streptococcus spp., Escherichia coli, and Klebsiella spp. Molecular studies have also identified multidrug resistance, methicillin resistance, beta-lactamases, virulence and biofilm genes, and mobile genetic elements in established and emerging mastitis pathogens, emphasizing their One Health importance. Sustainable control requires integrated udder health management rather than repeated empirical antimicrobial treatments. Priorities include routine screening, quantitative somatic cell monitoring, aseptic culture of persistent or recurrent cases, hygienic milking, individual teat drying, post-milking teat disinfection, clean and well-drained housing, appropriate nutrition, selective dry-period management, treatment records, and antimicrobial stewardship. Bangladesh also needs standardized case definitions, regional diagnostic services, competency-based farmer training, quality-based milk payments, residue monitoring, and coordinated surveillance of pathogens and antimicrobial resistance. This review synthesizes evidence from Bangladesh and proposes a phased, smallholder-compatible strategy to improve udder health, milk safety, animal welfare, and the sustainability of the dairy sector.

Res. Agric. Livest. Fish. 13(2): 309-340