Irrespective of how well drying off goes, most herds have some level of clinical mastitis to deal with during the calving period. An individual animal may have been treated with dry cow therapy, or a teat sealant, or combo therapy, but these approaches only lower the risk of a new clinical infection – they do not eliminate it all together. As we enter the busy time of spring calving, it is worth taking a moment to remind ourselves of some of the mastitis control strategies that are useful at this time. 
 
Reduce the chance of teat contact with mud as best you can. New clinical mastitis infections, through environmental bacteria, is a numbers game. The more mud and faecal material on the teat surface, for any reason, the greater the probability that a new infection can be established by the likes of Strep uberis and E coli. Of course, it is a case of balancing competing forces as springer/transition cows are run on tight pasture breaks leading up to calving and this may increase the risk of teat soiling. However, there is very sound evidence that the dirtier the udders and teats appear during the transition period, the higher the new infection risk so use the visual clues here when milking freshly calved cows to gauge your risk. 
 
Monitor the number of new clinical cases against the trigger level. Smart SAMM has recommended that, during the transition period (2 weeks prior to calving and 2 weeks after calving for an individual cow) the trigger point for action should be no greater than 8 clinical cases/100 cow calved/month. Again, with calving cows and managing calves, it is difficult to find time during the calving period to sit down and assess the animal health treatments you are recording, but in this case, it is worthwhile. If the number of new clinical mastitis infections is approaching, or greater than this trigger, it is well worthwhile asking your vet to assist you in exploring the causes further so action to reduce risk can be considered. Recall that every clinical case is worth around $250 to the dairy business so there is plenty of financial incentive to monitor, assess and take action if required. 
 
Take a milk sample immediately prior to inserting lactating cow treatment. If you find a new case for treatment, the teat must be disinfected prior to inserting the treatment tube so why not take a sterile milk sample for freezing as an insurance policy. If, in a number of weeks, the clinical case rate has risen above the trigger level, these frozen samples stored on farm will be invaluable in making sure that the mastitis bugs we think we are dealing with prove to be the ones actually causing the infection. This is an insurance against addressing an increase in new infection rate adequately and using appropriate treatment.