Mastitis in Dairy Cattle: Causes, Types, and Prevention

What is Mastitis?

Mastitis is inflammation of the mammary gland, almost always caused by bacterial infection. It is the most economically significant disease in commercial dairy cattle worldwide, costing dairy industries billions annually through reduced milk production, treatment costs, discarded milk, premature culling, and labor.

A cow with mastitis produces less milk, often of poorer quality (higher somatic cell count, altered protein and fat composition), and may require antibiotic treatment that renders milk unsaleable during the withdrawal period. In severe cases, mastitis leads to permanent udder damage, reduced future production potential, and death.

Contagious vs Environmental Mastitis

Mastitis is broadly categorized by the source of the infecting bacteria:

Contagious mastitis is caused by pathogens that spread from infected cows to uninfected cows primarily through the milking process — via the milking cluster, milker's hands, or udder cloths. The main contagious pathogens are:

• Staphylococcus aureus — the most difficult to cure; chronic subclinical infections persist in quarters for long periods
• Streptococcus agalactiae — highly contagious, but responds well to antibiotic treatment if identified early
• Mycoplasma species — highly contagious, no effective treatment, requires culling of affected animals

Contagious mastitis is controlled by practices that interrupt transmission during milking: between-animal cluster disinfection (using xxO Flush PA 5), post-milking teat dipping, and culling of chronically infected animals.

Environmental mastitis is caused by pathogens that naturally exist in the cow's environment — bedding, soil, manure, water. The main environmental pathogens are:

• Escherichia coli and other coliforms — typically cause acute clinical mastitis; shorter duration infections but higher acute risk
• Streptococcus uberis and Streptococcus dysgalactiae — can behave both as environmental and contagious pathogens

Environmental mastitis is controlled by improving housing hygiene and by post-milking teat protection that shields the teat canal during the post-milking open-canal period. Film-forming dips such as Vilnus F50 Active are particularly valuable for extended protection against environmental challenge.

The Role of Teat Hygiene

Pre-milking teat preparation with Vilnus LACO or Vilnus LA reduces the bacteria on the teat skin before milking, directly reducing both contagious and environmental transmission. Post-milking teat dipping with Vilnus 5000 Active or a film-forming product protects the teat canal during its most vulnerable period.

Contact AgroLyne to discuss a complete teat hygiene product selection for your mastitis prevention program.