Ivermectin for Horses

Equine · Equus caballus · typical adult weight 350.00–700.00 kg

Ivermectin is dosed at 0.2 mg/kg PO single dose in horses, per Eqvalan® Paste 1.87% [Product Label]. Merial; 2008. — 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. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Ivermectin is used in horses for GI strongyles, bots, pinworms. Routes documented in horses: PO. A typical adult horse weighs 350.00–700.00 kg. ExoticRx lists 1 cited dose rule for Ivermectin in horses, 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	Indication	Evidence	Source
PO	0.2 mg/kg	single dose	GI strongyles, bots, pinworms	Strong	Eqvalan® Paste 1.87% [Product Label]. Merial; 2008. — 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. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207

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	IM	Papich Saunders Handbook of Veterinary Drugs, 4th edp.451	• 200 mcg/kg (0.2 mg/kg) IM, oral paste, or oral solution. Administer once, or as
200	PO	Papich Saunders Handbook of Veterinary Drugs, 4th edp.452	• 200 mcg/kg ivermectin and 1 mg/kg praziquantel PO.

Printed doses in mg/kg for this drug and species, by source
Dose (mg/kg)	Route	Source	As printed
0.2	IM	Papich Saunders Handbook of Veterinary Drugs, 4th edp.451	• 200 mcg/kg (0.2 mg/kg) IM, oral paste, or oral solution. Administer once, or as

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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 horses 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 Horses?

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

How is Ivermectin administered in Horses?

Documented routes for Ivermectin in horses: PO.

What conditions does Ivermectin treat in Horses?

Ivermectin is indicated in horses for: GI strongyles, bots, pinworms.

What are the side effects of Ivermectin in Horses?

These are general warnings for Ivermectin across species; consult the horse 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 horse dosing

Fenbendazole Moxidectin Oxfendazole Ponazuril (Livestock)Praziquantel Pyrantel Pamoate

Ivermectin dosing in other species

African Clawed Frogs African Grey Parrots African Pygmy Hedgehogs Axolotls Ball Pythons Bearded Dragons Blue-and-Gold Macaws Budgerigars

See all species for Ivermectin See all drugs for Horses

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 horses — 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.