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).. 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

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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.

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.