Ivermectin for Sheep

Livestock · Ovis aries · typical adult weight 30.00–120.00 kg

Ivermectin is dosed at 0.2 mg/kg PO single dose in sheep, per Ivomec Sheep Drench Dewormer [Product Insert]. Merial — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.739 (2026-08-01). — Plumb's 10th ed (held) printed p.712, Ivermectin monograph spanning p.709-713; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — 21 CFR § 520.1195 (Ivermectin liquid), conditions of use for Sheep: 0.2-0.2 mg/kg. Related tolerances: 21 CFR § 556.344. Retrieved from the eCFR API, snapshot 2026-01-01. https://www.ecfr.gov/current/title-21/section-520.1195 — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Ivermectin is used in sheep for GI nematodes, GI nematodes (Haemonchus, Ostertagia, Trichostrongylus). Routes documented in sheep: PO. A typical adult sheep weighs 30.00–120.00 kg. ExoticRx lists 2 cited dose rules for Ivermectin in sheep, drawn from published veterinary references. Verify against current literature before clinical use.

US trade names: Ivomec, Heartgard

Contraindicated in Tortoise / Turtle

Tortoise / Turtle: Ivermectin causes fatal toxicosis in chelonians at doses other reptiles tolerateChelonians are far more sensitive than lizards and snakes: doses routine elsewhere in reptile practice have produced paralysis and death in turtles and tortoises. Do not use ivermectin in chelonians; use fenbendazole or another alternative. (The cited study did find 0.05 mg/kg IM tolerated in red-footed tortoises when not repeated inside 7 days, so the hazard is dose- and interval-dependent rather than absolute — but that margin is far too narrow to work to in a clinical setting.)

Dose ranges

Route	Dose	Frequency	Duration	Indication	Evidence	Source
PO	0.2 mg/kg	single dose	—	GI nematodes	Strong	Ivomec Sheep Drench Dewormer [Product Insert]. Merial — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.739 (2026-08-01). — Plumb's 10th ed (held) printed p.712, Ivermectin monograph spanning p.709-713; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — 21 CFR § 520.1195 (Ivermectin liquid), conditions of use for Sheep: 0.2-0.2 mg/kg. Related tolerances: 21 CFR § 556.344. Retrieved from the eCFR API, snapshot 2026-01-01. https://www.ecfr.gov/current/title-21/section-520.1195 — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207
PO	0.2 mg/kg	Once	Single dose	GI nematodes (Haemonchus, Ostertagia, Trichostrongylus)	Strong

What each reference text prints

Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.

Printed doses in mcg/kg for this drug and species, by source
Dose (mcg/kg)	Route	Source	As printed
200	PO	Papich Saunders Handbook of Veterinary Drugs, 4th edp.451	• 200 mcg/kg PO.

Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.

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Mechanism of action

Potentiates glutamate-gated chloride channels in invertebrate nerve and muscle cells, causing paralysis and death of parasites.

Side effects & warnings

TOXIC to MDR1-mutant dogs (Collies, Shelties, Aussies) at elevated doses. DO NOT use in chelonians (turtles/tortoises). Narrow safety margin in some species. Test MDR1 status before use in herding breeds.

Species-specific contraindications and adverse-reaction reports for sheep may differ from canine / feline reference data — consult the primary citations listed with each rule.

Frequently asked questions

What is the dose of Ivermectin for Sheep?

Ivermectin dose ranges in sheep, with cited source references: PO 0.2 mg/kg single dose; PO 0.2 mg/kg Once. Reference ranges from cited sources — verify against current literature before clinical use.

How is Ivermectin administered in Sheep?

Documented routes for Ivermectin in sheep: PO.

How long is Ivermectin given in Sheep?

Cited course lengths for Ivermectin in sheep include: Single dose. Duration depends on the indication — match it to the specific dose rule in the table above.

What conditions does Ivermectin treat in Sheep?

Ivermectin is indicated in sheep for: GI nematodes, GI nematodes (Haemonchus, Ostertagia, Trichostrongylus).

What are the side effects of Ivermectin in Sheep?

These are general warnings for Ivermectin across species; consult the sheep dosing table above for species-specific guidance. TOXIC to MDR1-mutant dogs (Collies, Shelties, Aussies) at elevated doses. DO NOT use in chelonians (turtles/tortoises). Narrow safety margin in some species. Test MDR1 status before use in herding breeds.

Other Antiparasitic drugs with sheep dosing

Albendazole Closantel (Livestock)Decoquinate Diclazuril (Livestock)Fenbendazole Lasalocid Levamisole Moxidectin Toltrazuril Triclabendazole

Ivermectin dosing in other species

Cattle Chickens Goats Swine Turkeys African Clawed Frogs African Grey Parrots African Pygmy Hedgehogs

See all species for Ivermectin See all drugs for Sheep

Why a species-specific page? Ivermectin pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in sheep — the rules above are the citations specific to this species, not generic recommendations.

Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.