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Erythromycin for Horse

Equine · Equus caballus · typical adult weight 350.00–700.00 kg

Erythromycin is used in horse for Rhodococcus equi pneumonia (foals), Rhodococcus equi in foals (with rifampin). Routes documented in horse: PO. A typical adult horse weighs 350.00–700.00 kg. ExoticRx lists 2 cited dose rules for Erythromycin in horse, drawn from published veterinary references. Verify against current literature before clinical use.

Trade names: Erythro-100, Gallimycin

Dose ranges

RouteDoseFrequencyDurationIndicationEvidenceSource
PO25 mg/kgq6-8h4-9 weeksRhodococcus equi pneumonia (foals)StrongPlumb's Veterinary Drug Handbook, 9th Ed
PO25–37.5 mg/kgq8-12h4-12 weeksRhodococcus equi in foals (with rifampin)StrongPlumb's Veterinary Drug Handbook

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Mechanism of action

Binds 50S ribosomal subunit, inhibiting translocation of peptidyl-tRNA, blocking bacterial protein synthesis.

Side effects & warnings

CONTRAINDICATED in rabbits and hindgut fermenters. Prokinetic at sub-antimicrobial doses. GI upset common. Hepatotoxicity reported. Strong CYP inhibitor.

Species-specific contraindications and adverse-reaction reports for horse may differ from canine / feline reference data — consult the primary citations listed with each rule.

Other Antibiotic drugs with horse dosing

AmikacinAmoxicillinAmpicillinAzithromycinCefquinome (Livestock)CeftiofurChloramphenicolDoxycyclineEnrofloxacinGentamicinMarbofloxacin (Livestock)Metronidazole

Erythromycin dosing in other species

CatCattleDog
See all species for ErythromycinSee all drugs for Horse

Why a species-specific page? Erythromycin pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in horse — the rules above are the citations specific to this species, not generic recommendations.

Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.