Closantel
Closantel acts against susceptible liver flukes and selected blood-feeding parasites. Activity depends on parasite stage and formulation.
Group
Salicylanilide anthelmintic
Mechanism of Action
Uncouples oxidative phosphorylation, reducing parasite ATP production.
Dose Rates
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible liver fluke and blood-feeding parasites | 10 mg/kg | PO | Once | Oral regimen; efficacy varies with parasite species, stage and resistance. |
Sheep
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible liver fluke and blood-feeding parasites | 10 mg/kg | PO | Once | Oral regimen; efficacy varies with parasite species, stage and resistance. |
Indications
- Susceptible fasciolosis
- Haemonchus and other label-susceptible blood-feeding parasites
Contraindications
- Do not overdose; avoid use in species not supported by the formulation.
Interactions
- Other flukicides may duplicate treatment; combination doses require their own verified directions.
Adverse effects
- Anorexia, ataxia and visual disturbance, especially with overdose.
Toxicity
Overdose can cause retinal/optic nerve injury and permanent blindness. There is no specific antidote; prevent further exposure and provide supportive care.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Zenvet oral solution 15% 15% w/v = 150 mg/mL; do not inject. | Oral Liquid | 150 mg / mL | PO |
| Zenvet 1000 mg bolus | Tablet | 1000 mg / tablet | PO |
| Zenvet 6000 mg bolus | Tablet | 6000 mg / tablet | PO |
Monitoring and Administration
Weigh accurately and calibrate dosing equipment. Assess efficacy rather than repeating ineffective treatment in resistant fluke populations.
Oral and injectable products have different concentrations and directions; milk restrictions are product-specific.