Pharmacology of Aminoglycosides in Cattle

Abstract

Aminoglycosides (e.g. gentamicin, neomycin, dihydrostreptomycin) are potent and in many instances highly effective antibiotics that are available for parenteral administration; their use in cattle is only by prescription, and in most instances only in an extralabel situation, for systemic gram-negative infections. Oral absorption is minimal except in neonatal animals; distribution of drug out of the bloodstream into tissues is proportional to extracellular fluid, and is greater in young animals that have a higher extracellular fluid volume. Their propensity for accumulation and slow release from renal tissues makes their use in feedlot cattle unwise because of the likelihood of violative tissue residues. Spectinomycin is not an aminoglycoside but rather is an aminocyclitol, with less propensity for accumulation and slow release from kidneys.