Bacteriological recovery after intramuscular or intracisternal spiramycin-based drying-off therapy

Systemic (intramuscular, IM) vs, local (intracisternal, IC) routes of spira mycin-based drying-off therapy were compared for efficacy on 65 Staphylococ cus aureus infected udder quarters of 38 dairy cows. Single-dose (30,000 IU /kg) IM treatment (single IM group) resulted in a similarly low bacteriolog ical recovery rate (14%) as seen in the untreated controls (18%). IM treatm ent (30,000 IU/kg) on 4 consecutive days (4 IM group) resulted in significa ntly higher quarter-based recovery rates than that in the single IM group. The bacteriological recovery rates obtained in the intracisternal and 4 IM groups were quite similar but remained below 50%. Based on these findings a s well as on the high cost of the repeated intramuscular treatment regime t here is no reason to give extra preference to the systemic application of s piramycin at drying off in the practice.