Streptococcus uberis and Staphylococcus aureus are important
mastitis pathogens in dairy cows in the entire world. Recent publications showed that an extended
therapy can be more efficient in combating such intramammary
infections. The objective of this study was to evaluate the effect of an extended intramammary
therapy to treat moderate and severe
mastitis cases in lactating dairy cows under field conditions in northern Germany. From December 2005 to August 2007, a total of 157 clinical
mastitis cases on 10 farms in northern Germany were enrolled in the study and randomly assigned (blocked by parity and body temperature) to one of two treatment groups (intrammammary
lincomycin/
neomycin 1.5-d (ALK) or 5-d (ALL)). Clinical, microbiological and cytomicrobiological cure rates were evaluated. Treatments were initiated before culture results. Cows were observed and evaluated on d 1 to 6, 19 and 26. Six cases in 157 (3.8%) resulted in a
therapy change in between 48 h after
mastitis detection. Overall, treatments were not significantly different to controls regarding clinical cure rate. However, when the microbiological cure rate was evaluated, differences were observed. ALL appeared form
infections. We conclude that in farms with Streptococcus uberis
mastitis, the 5-d extended
lincomycin/
neomycin treatment regimen was significantly more efficient in microbiological cure than the standard 1.5-d treatment.