Antibacterial describes any drug or substance that acts against bacteria, either by inhibiting their growth (bacteriostatic) or by killing them outright (bactericidal). The term is broader than antibiotic: all antibiotics are antibacterials, but some antibacterials — such as certain chemical disinfectants, wound flushes, and topical silver preparations — are not classified as antibiotics because they are not derived from or modeled on microbial metabolites.
In equine practice, antibacterials are used systemically for bacterial infections of the respiratory tract, skin, joints, and reproductive system, and topically for wound care, ophthalmic infections, and thrush in the hoof. The choice between bacteriostatic and bactericidal action matters in immunocompromised horses or when treating infections in poorly vascularized tissues like bone, where the immune system cannot clear bacteria that have merely been growth-arrested.
Responsible antibacterial use in horses has become a veterinary priority as multi-drug resistant organisms — including methicillin-resistant Staphylococcus and Salmonella — have been isolated from equine patients and can pose a zoonotic risk. Culture and sensitivity testing before prescribing a systemic antibacterial, rather than empirical broad-spectrum treatment, is now the standard of care for non-emergency infections. Topical antibacterials used on wounds should be chosen for efficacy against the target organism without disrupting healthy tissue healing; many commonly used products (hydrogen peroxide, undiluted iodine) are more damaging to granulation tissue than they are to bacteria. See hoof abscess management for a practical example of antibacterial use in a common acute condition.
Further Reading
- Antibacterial agents — Wikipedia on the distinction between antibacterials and antibiotics, with mechanism overviews.
- Antibacterial drugs in veterinary medicine — Merck Veterinary Manual reference covering spectrum, pharmacodynamics, and equine clinical applications.