Neomycin is an aminoglycoside antibiotic that displays bactericidal activity against gram-negative aerobic bacilli and some anaerobic bacilli where resistance has not yet arisen. Neomycin is used to treat bacterial gastrointestinal infections of cattle, sheep, pigs, goats and poultry by the oral route and to treat mastitis by intramammary administration. Caution: Neomycin should not used in combination with Amphotericin B or Penicillins due to increased risk of renal damage and low potassium blood levels.