# Abamectin: veterinary dose and monograph

> Abamectin is a veterinary antiparasitic. An avermectin (macrocyclic lactone) endectocide used in LIVESTOCK for GI roundworms, lungworm, and ectoparasites (mites, lice) — closely related to ivermectin, available as injectables, oral drenches and pour-ons, and frequently as… Indications include GI nematodes (Haemonchus, Ostertagia, Trichostrongylus, Cooperia, etc.) in cattle/sheep/goats; lungworm (Dictyocaulus); mites (mange) and lice. This monograph lists 2 reference doses for cattle and sheep, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/abamectin · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Antiparasitic
- **Also known as:** Avermectin B1, Abamectin (livestock endectocide)
- **Species with doses:** Cattle and Sheep
- **General dose range:** 0.2 mg/kg SC single dose (repeat per cycle) — check the species tables for the indication
- **Routes:** SC, PO
- **Last reviewed:** 1 October 2026

## Indications

- GI nematodes (Haemonchus, Ostertagia, Trichostrongylus, Cooperia, etc.) in cattle/sheep/goats
- Lungworm (Dictyocaulus)
- Mites (mange) and lice
- Broad endo/ectoparasite control (often as combination drenches)

## Abamectin dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Cattle

*Abamectin doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Endo/ectoparasites (injectable) | 0.2 mg/kg | SC | single dose | — | 35d slaughter |

- Endo/ectoparasites (injectable): 0.2 mg/kg SC (1 mL/50 kg of 1 %); not for lactating dairy. Label-sourced — neither Papich 5e nor Plumb’s has an abamectin monograph; follow the local product label and withdrawal.

### Goats

*Abamectin doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: Neither Papich 5e nor Plumb’s has an abamectin monograph, and the previous goat row extrapolated a higher dose with no source.

### Sheep

*Abamectin doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| GI nematodes (oral drench) | 0.2 mg/kg | PO | single dose | — | Withdrawal NOT established — treat as extra-label |

- GI nematodes (oral drench): Often as a combination drench; check for ML resistance. Label-sourced — no Papich 5e or Plumb’s monograph; follow the product label and withdrawal. Label dose 0.2 mg/kg (200 µg/kg) PO.

### Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

*Abamectin doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Endo/ectoparasites (injectable) | 0.2 mg/kg | SC | single dose | — | 35d slaughter |

- Endo/ectoparasites (injectable): 0.2 mg/kg SC (1 mL/50 kg of 1 %); not for lactating dairy. Label-sourced — neither Papich 5e nor Plumb’s has an abamectin monograph; follow the local product label and withdrawal.

## Contraindications

Accidental exposure of MDR1 (ABCB1-Δ) herding-breed dogs (neurotoxicity — this is a livestock drug). Environmental release near waterways (aquatic toxicity). Lactating dairy producing human milk (per product). Observe meat/withdrawal periods. Known hypersensitivity.

## Species-specific warnings

> **Caution:** Dogs: A livestock macrocyclic lactone — MDR1 (ABCB1-1Δ) breeds are highly sensitive to accidental ingestion (coma/death). Keep away from dogs.

> **Caution:** Goats: Off-label in goats — higher dose needed, withdrawal not established; extend meat/milk withdrawal conservatively.

## Adverse effects

- Transient injection-site reaction
- Neurotoxicity only at gross overdose or in MDR1-deficient animals
- Environmental toxicity to dung beetles/aquatic invertebrates

## Drug interactions

- P-glycoprotein inhibitors (e.g. spinosad, ketoconazole): increased CNS exposure/toxicity
- Combination drenches: levamisole/triclabendazole add complementary spectra
- Concurrent CNS depressants: additive at high exposure

## Pregnancy and lactation

Considered safe in pregnant livestock at label doses; widely used in breeding stock.

## Monitoring

- Faecal egg count reduction (efficacy/resistance)
- Meat/withdrawal compliance
- Resistance surveillance (ML resistance is rising) and class rotation
- Neurologic status only if overdose suspected

## Toxicity and overdose

Very wide margin in normal livestock; toxicity (mydriasis, ataxia, tremor, depression, coma) appears only at gross overdose or in MDR1-deficient dogs that access the product. Environmental toxicity to dung-dwelling and aquatic invertebrates is a class concern.

Management: No specific antidote. Supportive/intensive care; benzodiazepines for seizures; INTRAVENOUS LIPID EMULSION for severe macrocyclic-lactone neurotoxicity (lipophilic). Recovery may take days–weeks.

## Clinical pearls

- An ivermectin-class livestock endectocide — broad GI-worm/lungworm/ectoparasite cover, often sold as combination drenches
- Keep away from MDR1-prone dogs (livestock product) and dispose of dung/run-off responsibly (dung-beetle/aquatic toxicity)
- Macrocyclic-lactone resistance is widespread in small-ruminant worms — use FECRT and rotate classes
- Goats need a higher dose (faster metabolism) with conservative withdrawal

## Mechanism of action

Binds glutamate-gated chloride channels (and GABA channels) in nematode and arthropod neuromuscular tissue, causing chloride influx, hyperpolarisation, paralysis and death. Mammals are normally spared (channels are behind the blood–brain barrier and P-glycoprotein effluxes the drug) — the basis of MDR1 sensitivity when that protection fails.

## Formulations and products

- Injectable 10 mg/mL (1 %)
- Oral drench / pour-on (livestock)
- Combination drench (with levamisole/triclabendazole)
- Abamectin injectable / drench (Various) — 1 % injectable; oral/pour-on; combination drenches, Injection / drench / pour-on

## Storage

Injectable/drench/pour-on: 15–30 °C, protect from light/frost; keep away from waterways.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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- [Amitraz](https://vetmasterji.com/drugs/amitraz)
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- [Buparvaquone](https://vetmasterji.com/drugs/buparvaquone)
- [Clorsulon](https://vetmasterji.com/drugs/clorsulon)

## Frequently asked questions

### What is the dose of Abamectin for cattle?

Reference doses for Abamectin in cattle: 0.2 mg/kg SC single dose (Endo/ectoparasites (injectable)). Confirm against the label and the patient before use.

### Can Abamectin be given to goats?

Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species (No reference dose for this species).

### What is the dose of Abamectin for sheep?

Reference doses for Abamectin in sheep: 0.2 mg/kg PO single dose (GI nematodes (oral drench)). Confirm against the label and the patient before use.

### What is the withdrawal period for Abamectin?

Cattle, SC (Endo/ectoparasites (injectable)): 35d slaughter; Sheep, PO (GI nematodes (oral drench)): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Abamectin not be used?

Accidental exposure of MDR1 (ABCB1-Δ) herding-breed dogs (neurotoxicity — this is a livestock drug). Environmental release near waterways (aquatic toxicity). Lactating dairy producing human milk (per product). Observe meat/withdrawal periods. Known hypersensitivity.

### What are the side effects of Abamectin in animals?

Transient injection-site reaction; Neurotoxicity only at gross overdose or in MDR1-deficient animals; Environmental toxicity to dung beetles/aquatic invertebrates.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.