Selected Antimicrobial Information – Equine
Erythromycin [Equine]
Restriction Status
Unrestricted
Dose
| Species | Usage | Dose |
|---|---|---|
| Horses |
For treatment of Rhodococcus equi in foals | 20-25mg/kg PO q8h (extra-label use) |
| For treatment of Lawsonia intracellularis in foals | 25mg/kg PO q6-8h (extra-label use)
10mg/kg PO q12h when used with rifampin (extra-label use) |
Brand Name(s)
Gallimycin®
Background
Erythromycin is a concentration-dependent, primarily bacteriostatic macrolide antibiotic. It may be bactericidal at high doses. Erythromycin is active against Gram-positive aerobes. There is also some efficacy against non-enteric Gram-negatives such as Actinobacillus spp. and Pasteurella spp., and anaerobes such as Clostridium spp. and Fusobacterium spp. Distribution throughout the body is wide, and excretion is primarily in bile. .
Acceptable Uses
- Treatment of Rhodococcus equi pneumonia in foals when used in combination with rifampin.
- Treatment of Lawsonia intracellularis (equine proliferative enteropathy) in foal; used with or without rifampin.
Unacceptable Uses
- N/A
Formulations Available within the OSU Pharmacy
- Currently no oral erythromycin formulations available within the OSU pharmacy; available upon request
Notes
- Severe and fatal colitis has been associated with macrolide use in adult horses and thus should be avoided in adults. Foals receiving treatment with a macrolide antibiotic should have their mouths rinsed out after to administration to prevent adverse effects to the mare.
- Macrolides have been associated with significant hyperthermia in treated foals due to off-target effects on apocrine sweat glands; treated foals should not be housed in direct sunlight for prolonged periods of time and should have access to a climate-controlled enclosure.
