Mastitis — inflammation of the udder — remains the most economically costly and welfare-significant disease in dairy farming globally. Understanding its causes, risk factors, and evidence-based prevention strategies allows producers to substantially reduce incidence and improve both cow welfare and farm profitability.
Pathogenesis
Mastitis occurs when pathogens penetrate the teat canal and proliferate in the milk-producing tissue. Bacterial species are classified by epidemiology:
- Contagious pathogens (spread cow-to-cow via milking): Staphylococcus aureus, Streptococcus agalactiae — spread via milking equipment and hands; persist within the herd
- Environmental pathogens (from bedding, soil, faeces): E. coli, Streptococcus uberis, Klebsiella — clinical disease from environmental exposure; high incidence in poorly managed housing
Five-Point Mastitis Control Plan
The AHDB/BCVA Five-Point Plan is the evidence-based framework for mastitis control:
- Teat dipping (post-milking): Teat dip application to all teats immediately after milking prevents pathogen entry; reduces contagious mastitis by 50%+
- Dry cow therapy (DCT): Antibiotic infusion at drying off treats existing subclinical infections and prevents new infections in the dry period; selective DCT using CMT testing reduces unnecessary antibiotic use while maintaining efficacy
- Early detection and treatment: Rapid identification and treatment of clinical cases reduces pathogen shedding and cow suffering; California Mastitis Test (CMT) and SCC monitoring enable subclinical detection
- Culling of chronic cases: Persistently infected cows act as reservoirs; culling or segregation protects herd
- Milking machine maintenance: Properly functioning liners and pulsation rates prevent teat end damage that predisposes to infection
Environmental Mastitis Prevention
Environmental mastitis control focuses on reducing pathogen exposure:
- Clean, dry, well-maintained bedding (cubicle mats, deep sand, rubber crumb) — freshened twice daily minimum
- Adequate cubicle dimensions to prevent contamination of udder and teats
- Good passageway drainage and cleaning frequency
- Pre-milking teat preparation (washing, drying, forestripping) for heavily contaminated cows
Somatic Cell Count Monitoring
Monthly individual cow SCC testing (through milk recording) identifies high SCC cows requiring investigation. Bulk milk SCC is a herd health indicator. Target individual cow SCC <200,000 cells/mL; bulk milk SCC <100,000 cells/mL for premium quality. Regular SCC review with veterinary guidance supports proactive herd management.
Welfare Significance
Clinical mastitis causes significant acute pain — febrile, toxaemic cows show dramatic welfare compromise. Effective analgesia (NSAIDs) must accompany antibiotic treatment in clinical cases. Chronic subclinical mastitis causes lower-grade but persistent welfare impacts on production, immune function, and longevity. Mastitis prevention is therefore simultaneously a welfare, antibiotic stewardship, and economic priority for dairy producers.