Amoxicillin Resides in Milk of Holstein Cows With Double or Triple Intramammary Administration of Amoxicillin-Potassium Clavulanate

The aim of this study was to determine differences in residue elimination of amoxicillin (AMX) in cow ́s milk, after intramammary administration of a pharmaceutical preparation of AMX plus potassium clavulanate (CLV), either in healthy or in spontaneous cases of clinical mastitis, and following label instructions or administering the preparation in an extra-label manner. Twelve lactating healthy Holstein/Friesan cows in production and negative to clinical mastitis were treated with a commercial brand of intramammary AMX/CLV (300 mg of AMX and 60 mg of CLV), administered every 12 h for 3 consecutive days (CL group), as recommended on the label. Twelve cows with clinical mastitis, determined by California test, somatic cell count, microbiological culture and physical aspect of the milk, were dosed as group CL (Exp-L group). Twelve cows, also affected with mastitis, were treated with double dose for three days (Exp-EL1 group). Finally, a fourth group of 12 cows with mastitis were treated in an extra-label manner by tripling the referred dose (Exp-EL2 group). After the last administration, milk samples from all the Amoxicillin Resides in Milk of Holstein Cows With Double or Triple Intramammary Administration of Amoxicillin-Potassium Clavulanate