Staph Aureus Mastitis: Have We Learned Anything in 50 Years?10 June 2014
Science has given us a great deal of knowledge about mastitis, but a Missouri veterinarian warns that basic lessons still need to be put into practice.
- Have we learned anything about Staphylococcus aureus mastitis in the last 50 years? Yes.
- Has what we’ve learned changed the basic premise that milking time hygiene is the main critical control point and S. aureus can be refractory to treatment? No.
According to John Middleton, University of Missouri, the ultimate decisions about how to manage Staph aureus mastitis in a given herd depend on the contagiousness, persistence and inflammatory nature of the infecting strains.
Addressing the National Mastitis Council (NMC), Mr Middleton said that use of historical data on new infection rates, somatic cell count and response to therapy will be valuable tools in making management decisions.
Culturing cows and having the isolates strain-typed may be necessary in some herds to better understand how contagious Staph aureus is in that given herd.
If most infections are the result of a single strain causing chronic infections that are refractory to treatment, accelerated culling may be the only mechanism to maintain milk quality in the bulk tank.
Alternatively, sporadic cases of Staph aureus intramammary infections caused by isolates with no consistent strain type may not have herdwide implications and, therefore, management strategies can be applied at the level of the individually infected cow.
At this time, vaccination against Staph aureus is not recommended, with the possible exception of herds with a high incidence of clinical Staph aureus mastitis or to prevent intramammary infections in heifers using a hyper-immunization scheme.