This specialized formulation is active against both Gram-positive and Gram-negative organisms, including Streptococcus agalactiae, penicillin-resistant and sensitive Staphylococci, Corynebacterium, Arcanobacteria species, Escherichia coli, and other susceptible Gram-negative bacteria. With Cloxacillin benzathine and Ampicillin trihydrate in a long-acting base, Masti-Ban maintains potent antibacterial levels in the dry cow udder for up to 10 weeks. Plus, it's gentle on udder tissue, ensuring the health and well-being of your valuable dairy herd. Trust Masti-Ban for comprehensive mastitis defense and enhanced udder health.