Vetdrugs 2.0Oxfendazole is a benzimidazole anthelmintic and the sulfoxide metabolite of fenbendazole. It is used against susceptible gastrointestinal nematodes, lungworms and selected tapeworms. Established livestock and equine applications are supplemented by some extra-label companion-animal uses. Parasite coverage depends on the host, formulation and susceptible life stages.
Group
Benzimidazole anthelmintic
Mechanism of Action
Oxfendazole binds parasite beta-tubulin and inhibits polymerization into functional microtubules. Disruption of intracellular transport and nutrient handling impairs glucose uptake and depletes energy stores. These effects progressively compromise parasite survival. Activity against individual nematodes or cestodes depends on drug exposure, developmental stage and target-associated susceptibility.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Oslerus osleri | 10 mg/kg | PO | Every 24 h | Up to 28 days |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible internal parasites | 10 mg/kg | PO | Once | Cattle may require reassessment/repetition after 4-6 weeks; do not extrapolate a repeat interval to other species. |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible internal parasites | 4.5 mg/kg | PO | Once | Cattle may require reassessment/repetition after 4-6 weeks; do not extrapolate a repeat interval to other species. |
Pigs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible internal parasites | 3–4.5 mg/kg | PO | Once | Cattle may require reassessment/repetition after 4-6 weeks; do not extrapolate a repeat interval to other species. |
Sheep
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible internal parasites | 5 mg/kg | PO | Once | Cattle may require reassessment/repetition after 4-6 weeks; do not extrapolate a repeat interval to other species. |
Goats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible internal parasites | 7.5 mg/kg | PO | Once | Cattle may require reassessment/repetition after 4-6 weeks; do not extrapolate a repeat interval to other species. |
Indications
- Treatment or control of susceptible gastrointestinal nematodes, Dictyocaulus lungworms and selected Moniezia tapeworms in cattle.
- Treatment of susceptible equine ascarids, strongyles or pinworms using a supported product or regimen.
- Treatment of selected susceptible internal parasites in sheep, goats or other supported livestock species.
- Extra-label treatment of Oslerus osleri infection in dogs, with limited regimen-specific clinical evidence.
Contraindications
- Cited cattle product excludes female dairy cattle of breeding age; use cautiously in sick or debilitated horses.
Interactions
- Bromsalan flukicides have been associated with abortions in cattle and deaths in sheep when combined with oxfendazole.
Adverse effects
- Adverse effects are uncommon at recommended doses; hypersensitivity to dying parasites is possible.
Toxicity
Generally has a broad safety margin; provide supportive treatment for clinically significant overexposure.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Synanthic oral suspension 9.06% | Oral Liquid | 90.6 mg / mL | PO |
| Synanthic oral suspension 22.5% A product-specific intraruminal method is also described for the 22.5% presentation; it must not be replaced by IV, IM or SC injection. | Oral Liquid | 225 mg / mL | PO |
Monitoring and Administration
Shake suspension; determine accurate body weight and assess anthelmintic resistance.
The 22.5% intraruminal presentation and oral suspension have different administration requirements. Do not assign an intraruminal injection to IV, IM or SC.
Synanthic cattle meat withdrawal 7 days; not for dairy females of breeding age.