Disease-causing bacteria are called pathogens. The most common mastitis pathogens are found in the udder tissues, spreading from cow-to-cow (contagious pathogens) or in the herd's surroundings (environmental pathogens), such as bedding materials, manure, and soil.
This distinction may be important when assessing the challenges present in a herd and the measures which may be taken to reduce or treat mastitis:
Contagious pathogens that cause mastitis tend to live on the cow's udder and teat skin and transfer from an affected cow (or quarter) to unaffected cow (or quarter) during milking. You can browse https://www.licautomation.com/products/saber-scc-somatic-cell-count/ to know more about mastitis in cow’s treatment.
They adhere easily to the skin, colonizing the teat end and then 'grow' into the teat canal, where infection occurs; because of this, post-milking teat disinfection and dry cow therapy play an important role in controlling contagious mastitis.
Farms with a high level of contagious mastitis often have high Somatic Cell Counts (SCC) with relatively normal Bactoscan results.
Environmental mastitis pathogens – present in the housing and bedding – can transfer during milking or between milkings, when the cow is loafing, eating or lying down. The pathogen can enter the teat canal by force during milking, for example, when liner slippage occurs.
These environmental pathogens do not generally possess the same ability as contagious pathogens to adhere to and colonize the teat; dry cow therapy has little value in their control as these kinds of infections do not carry from one lactation to the next.
Mastitis pathogens can infect cows both during the dry period and when cows are lactating, and it is important to identify and recognize the source of these infections, as approaches to control, prevention and treatment of the pathogen's effects can differ according to whether the infection occurs when the cow is dry, or in lactation.