Erythromycin for Dogs – Antibiotic + Prokinetic
Erythromycin has dual use:
- Antibiotic (gram-positive, atypical, Campylobacter)
- Prokinetic (low dose for gastric emptying)
Dose by Use
| Use | Dose | Frequency |
|---|---|---|
| Antibiotic | 10-20 mg/kg | Every 8 hours |
| Prokinetic | 0.5-1 mg/kg (low) | Every 8 hours |
| Campylobacter | 10-15 mg/kg | Q8h x 5-7 days |
Dose Reference Table
Antibiotic (10 mg/kg)
| Weight | Per Dose |
|---|---|
| 5 kg | 50-100 mg |
| 10 kg | 100-200 mg |
| 20 kg | 200-400 mg |
| 30 kg | 300-600 mg |
| 40 kg | 400-800 mg |
Prokinetic (0.5-1 mg/kg)
| Weight | Per Dose |
|---|---|
| 5 kg | 2.5-5 mg |
| 10 kg | 5-10 mg |
| 20 kg | 10-20 mg |
Prokinetic Mechanism
- Activates motilin receptors in upper GI
- Promotes gastric emptying
- Less effective than cisapride but available
- Sub-antimicrobial dose (no resistance + less GI upset)
âš Significant Drug Interactions (CYP3A4 Inhibitor)
- Digoxin – markedly increased levels
- Cyclosporine – increased levels
- Theophylline – toxicity risk
- Fluoroquinolones – QT prolongation
- Statins – rhabdomyolysis risk
- Warfarin – increased anticoagulation
- Benzodiazepines – increased levels
- Many others
Side Effects
Very Common
- GI upset (vomiting, diarrhea, anorexia)
- More common than azithromycin
- Abdominal pain
Less Common
- QT prolongation
- Hepatic enzyme elevations
- Cholestatic hepatitis (rare, serious)
Azithromycin Often Preferred
For antibiotic use, azithromycin generally preferred:
- Better tolerance
- Fewer drug interactions
- Once-daily dosing
- Pulse dosing capability
Frequently Asked Questions
How much erythromycin for my dog?
DEPENDS on use. ANTIBIOTIC: 10-20 mg/kg PO every 8 hours. EXAMPLES (10 mg/kg): 1) 5 kg = 50-100 mg per dose; 2) 10 kg = 100-200 mg; 3) 20 kg = 200-400 mg; 4) 30 kg = 300-600 mg; 5) 40 kg = 400-800 mg. PROKINETIC (gastric emptying): 0.5-1 mg/kg q8h – LOW dose. EXAMPLES: 5 kg = 2.5-5 mg; 10 kg = 5-10 mg. TABLETS 250 mg + suspensions. With food preferred (reduces GI upset). Q8H dosing essential. AZITHROMYCIN often preferred for antibiotic use due to better tolerance, fewer drug interactions, once-daily dosing. Prokinetic use less common than cisapride but available.
What are the side effects of erythromycin in dogs?
GI UPSET very common – the major issue. SIDE EFFECTS: 1) VOMITING (very common); 2) DIARRHEA; 3) ANOREXIA; 4) Abdominal pain; 5) GI cramping; 6) Hepatic enzyme elevations; 7) Cholestatic hepatitis (rare but serious); 8) QT prolongation (cardiac); 9) Allergic reactions; 10) Ototoxicity rare. WORSE GI SIDE EFFECTS than other macrolides (azithromycin, clarithromycin) – many dogs don’t tolerate. DRUG INTERACTIONS (CYP3A4 inhibitor – potent): 1) DIGOXIN markedly increased – toxicity risk; 2) CYCLOSPORINE increased; 3) THEOPHYLLINE toxicity; 4) Fluoroquinolones – QT prolongation additive; 5) STATINS – rhabdomyolysis; 6) WARFARIN – bleeding; 7) Many others – CHECK before combining. MANAGEMENT: 1) With food reduces GI upset; 2) Lower dose if tolerated; 3) Switch to azithromycin if intolerable; 4) Probiotics adjunct; 5) Anti-emetics short-term. ALTERNATIVES: 1) AZITHROMYCIN – better tolerance, once-daily, fewer interactions; 2) CLINDAMYCIN – similar spectrum, fewer drug interactions; 3) CEPHALEXIN – alternative for gram-positive.
Can erythromycin be used as a prokinetic for my dog?
YES – LOW DOSE used for gastric emptying. PROKINETIC DOSE: 0.5-1 mg/kg PO every 8 hours (SUB-ANTIMICROBIAL – much lower than antibiotic 10-20 mg/kg). MECHANISM: stimulates MOTILIN receptors in upper GI – promotes gastric emptying + small intestinal motility. INDICATIONS: 1) Gastric stasis (delayed emptying); 2) Ileus; 3) Post-surgical recovery; 4) Megaesophagus adjunct (less effective than cisapride); 5) Idiopathic delayed gastric emptying. ADVANTAGES of low dose: 1) Less GI upset than antimicrobial dose; 2) NO antimicrobial resistance development; 3) Targeted effect on motility; 4) Available widely; 5) Cheaper than cisapride often. COMPARED to CISAPRIDE: 1) Cisapride more effective prokinetic; 2) Cisapride compounded (not commercially available); 3) Erythromycin often used as alternative or adjunct; 4) Some protocols combine both. EXAMPLES: 1) 5 kg = 2.5-5 mg q8h; 2) 10 kg = 5-10 mg q8h; 3) 20 kg = 10-20 mg q8h; 4) 30 kg = 15-30 mg q8h. Often compounded into liquid for precise low-dose administration. Discuss with vet for prokinetic protocol.
Related PuppaDogs Calculators
Continue building your dog’s personalised care plan with these related PuppaDogs calculators:
- Dog Pregnancy / Whelping Due-Date Calculator
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References & Further Reading
The dosing ranges and safety information on this page are drawn from the following veterinary references. Always defer to your own veterinarian and the manufacturer’s label for your specific product.
- Plumb DC. Erythromycin.
- Boothe DM. Small Animal Clinical Pharmacology.
- Tang SC et al. Erythromycin as prokinetic in dogs.
- Hall JA. Diagnosis and management of motility disorders.
- PuppaDogs. Cisapride Calculator, Megaesophagus Calculator. puppadogs.com.
