Vet's Corner: a new herd health mastitis and SCC plan

I recently attended a cow with persistent mastitis that was responding poorly to treatment. The affected quarter never flared up, was never swollen and the cow herself had never been sick with mastitis.

As far as the farmer was concerned, it was just another case of what he termed E coli mastitis, which he anticipated might respond to a normal course of mastitis tubes.

I told my client that if the cow never got sick then it was unlikely to have been pure E coli mastitis. It was at that point that the client told me that one or two other quarters had proved positive on the CMT test and that he had treated them also.

This surprised him, as he was diligent about cleaning his hands and changing gloves in order not to transfer the infection from one quarter to another.

A sample was taken and it returned a positive diagnosis for mycoplasma bovis. Typically, this infection spreads from the lungs via the blood to the udder. The significance of this is that oftentimes more than one quarter will be affected.

When taking samples where mycoplasma bovis is suspected, it’s important milk from all four quarters need to be drawn into a single sample container. Another suspect cow with a high SCC also was positive for mycoplasma.

There is no cure for mycoplasma. Therefore, drying off or culling affected cows is essential, especially before they spread the infection.

The bulk tank SCC had been over 200,000 for the last few months and while this did not attract penalties, it was double what the normal level for this herd would be.

Once the two affected cows were taken out of the tank, the SCC reverted to 80,000. The bulk milk was also tested for mycoplasma bovis and that, thankfully, was negative, indicating that no more unsuspecting cases are lurking in the milking herd.

There is a mycoplasma bovis specific herd mastitis and SCC plan put in place for this herd:

This plan is reviewed every quarter.