Mastitis cure rate
The herd cure rate for mastitis defines how well the measures involved to treat cases of clinical mastitis perform. Like the incidence rate for mastitis, the cure rate for individual farms can be compared between farms and with national averages, but care is required as the cure rates for mastitis can vary wildly depending upon the pathogen responsible.
A bacterial cure may occur when antibiotics or the cow's own immune system reduce bacterial numbers sufficiently that the pathogen is no longer present in sufficient numbers to make the cow ill - either clinically or subclinically - but inflammation and damage to udder tissues will likely take longer to heal to provide a clinical cure. Some cases of mastitis may cure themselves without therapy, but even in cases that appear to be self-curing, antibiotic treatment will help to lower bacterial numbers and cell counts in the mildly mastitic cow.
If and when a clinical cure is achieved - where the cow's yield and cell count return to normal levels - will depend on a variety of factors; most importantly the pathogen involved, the cow's previous health history and immune status, how long the infection has lasted and what treatment regime is used. Because of this it is difficult to analyse what aspects of the cow's treatment were instrumental in bringing about the cure, therefore a simple definition of an actual cure taking place may be all that is possible under normal on-farm conditions.
Cure rate comparisons should also be strongly influenced by sporadic outbreaks of mastitis caused by pathogens such as E. coli, where bacterial cure rates may be good but the resultant damage to udder tissue - which may result in a quarter that is permanently lost or which might only recover after drying-off - means that a clinical cure is not achieved. In some cases, particularly with Staphylococcus aureus and Streptococcus uberis infections, much better clinical cure results are achieved when antibiotic treatment occurs at drying-off rather than during lactation.